CHAPTER TEN
Statistical Inferences about Two Populations
D
M
BApp
1.
Restaurateur Denny Valentine is evaluating two sites, Raymondville and
Rosenberg, for his next restaurant. Prevailing images of the two suburbs imply
that Raymondville residents (population 1) dine out less often than Rosenberg
residents (population 2). Denny plans to test this hypothesis using a random
sample of 81 families from each suburb. His null hypothesis is __________.
A.  1 < 2
B. 1 > 2
C. P1 = P2
D. 1  2
303
304
Test Bank
B
2.
A. 1 < 2
B. 1 > 2
C. P1 = P2
D. 1  2
M
BApp
D
3.
M
BCalc
A
M
BCalc
Restaurateur Denny Valentine is evaluating two sites, Raymondville and
Rosenberg, for his next restaurant. Prevailing images of the two suburbs imply
that Raymondville residents (population 1) dine out less often than Rosenberg
residents (population 2). Denny plans to test this hypothesis using a random
sample of 81 families from each suburb. His alternate hypothesis is __________.
Restaurateur Denny Valentine is evaluating two sites, Raymondville and
Rosenberg, for his next restaurant. Prevailing images of the two suburbs imply
that Raymondville residents (population 1) dine out less often than Rosenberg
residents (population 2). Denny commissions a market survey to test this
hypothesis. The market researcher used a random sample of 64 families from
each suburb, and reported the following: x 1 = 15 times per month, x 2 = 14 times
per month, S1 = 2, and S2 = 3. Assuming = .01, the critical Z value is
_________________.
A.
B.
C.
D.
4.
-1.96
1.96
-2.33
2.33
Restaurateur Denny Valentine is evaluating two sites, Raymondville and
Rosenberg, for his next restaurant. Prevailing images of the two suburbs imply
that Raymondville residents (population 1) dine out less often than Rosenberg
residents (population 2). Denny commissions a market survey to test this
hypothesis. The market researcher used a random sample of 64 families from
each suburb, and reported the following: x 1 = 15 times per month, x 2 = 14 times
per month, S1 = 2, and S2 = 3. Assuming = .01, the calculated Z value is
_________________.
A. 2.22
B. 12.81
C. 4.92
D. 3.58
Chapter 10: Statistical Inferences for Two Populations 305
D
5.
H
BCalc
D
A.
B.
C.
D.
6.
H
BCalc
B
H
BCalc
Restaurateur Denny Valentine is evaluating two sites, Raymondville and
Rosenberg, for his next restaurant. Prevailing images of the two suburbs imply
that Raymondville residents (population 1) dine out less often than Rosenberg
residents (population 2). Denny commissions a market survey to test this
hypothesis. The market researcher used a random sample of 64 families from
each suburb, and reported the following: x 1 = 15 times per month, x 2 = 14 times
per month, S1 = 2, and S2 = 3. Assuming = .01, the appropriate decision is
_________________.
reject the null hypothesis  1 <  2
accept the alternate hypothesis  1 >  2
reject the alternate hypothesis n1 = n2 = 64
do not reject the null hypothesis  1   2
Restaurateur Denny Valentine is evaluating two sites, Raymondville and
Rosenberg, for his next restaurant. Prevailing images of the two suburbs imply
that Raymondville residents (population 1) dine out less often than Rosenberg
residents (population 2). Denny commissions a market survey to test this
hypothesis. The market researcher used a random sample of 64 families from
each suburb, and reported the following: x 1 = 16 times per month, x 2 = 14 times
per month, S1 = 4, and S2 = 3. Assuming  = .01, the calculated Z value is
_________________.
A. 18.29
B. 6.05
C. 5.12
D. 3.20
7.
Restaurateur Denny Valentine is evaluating two sites, Raymondville and
Rosenberg, for his next restaurant. Prevailing images of the two suburbs imply
that Raymondville residents (population 1) dine out less often than Rosenberg
residents (population 2). Denny commissions a market survey to test this
hypothesis. The market researcher used a random sample of 64 families from
each suburb, and reported the following: x 1 = 16 times per month, x 2 = 14 times
per month, S1 = 4, and S2 = 3. Assuming  = .01, the appropriate decision is
_____.
A. reject the null hypothesis 1 < 2
B. accept the alternate hypothesis 1 > 2
C. reject the alternate hypothesis n1 = n2 = 64
306
Test Bank
D. do not reject the null hypothesis 1  2
A
8.
E
BApp
C
American First Banks' policy requires consistent, uniform training of employees at
all banks. Consequently, David Desreumaux, VP of Human Resources, is
planning a survey of mean employee training time in the Southeast region
(population 1) and the Southwest region (population 2). His null hypothesis is
___________.
A.
B.
C.
D.
9.




American First Banks' policy requires consistent, uniform training of employees at
all banks. Consequently, David Desreumaux, VP of Human Resources, is
planning a survey of mean employee training time in the Southeast region
(population 1) and the Southwest region (population 2). His alternate hypothesis
is _______.




E
BApp
A.
B.
C.
D.
B
American First Banks' policy requires consistent, uniform training of employees at
all banks. Consequently, David Desreumaux, VP of Human Resources, orders a
survey of mean employee training time in the Southeast region (population 1) and
the Southwest region (population 2). His staff randomly selected personnel
records of 81 employees from each region, and reported the following: x 1 = 30
hours, x 2 = 27 hours, S1 = 6, and S2 = 6. Assuming a two-tail test and  = .05,
the critical Z values are _________________.
10.
E
BCalc
A.
B.
C.
D.
-1.64 and 1.64
-1.96 and 1.96
-1.64 and 1.96
-2.33 and 2.33
Chapter 10: Statistical Inferences for Two Populations 307
C
11.
American First Banks' policy requires consistent, uniform training of employees at
all banks. Consequently, David Desreumaux, VP of Human Resources, orders a
survey of mean employee training time in the Southeast region (population 1) and
the Southwest region (population 2). His staff randomly selected personnel
records of 81 employees from each region, and reported the following: x 1 = 30
hours, x 2 = 27 hours, S1 = 6, and S2 = 6. Assuming a two-tail test and  = .05,
the calculated Z value is _________________.
M
BCalc
A.
B.
C.
D.
A
American First Banks' policy requires consistent, uniform training of employees at
all banks. Consequently, David Desreumaux, VP of Human Resources, orders a
survey of mean employee training time in the Southeast region (population 1) and
the Southwest region (population 2). His staff randomly selected personnel
records of 81 employees from each region, and reported the following: x 1 = 30
hours, x 2 = 27 hours, S1 = 6, and S2 = 6. Assuming a two-tail test and  = .05,
the appropriate decision is _________________.
12.
7.79
3.38
3.18
20.25
reject the null hypothesis 
accept the alternate hypothesis 
reject the null hypothesis 
do not reject the null hypothesis 
H
BCalc
A.
B.
C.
D.
A
American First Banks' policy requires consistent, uniform training of employees at
all banks. Consequently, David Desreumaux, VP of Human Resources, orders a
survey of mean employee training time in the Southeast region (population 1) and
the Southwest region (population 2). His staff randomly selected personnel
records of 81 employees from each region, and reported the following: x 1 = 30
hours, x 2 = 27 hours, S1 = 11, and S2 = 9. Assuming a two-tail test and  = .05,
the calculated Z value is _________________.
13.
M
BCalc
A.
B.
C.
D.
1.90
6.04
1.20
12.15
308
Test Bank
B
14.
American First Banks' policy requires consistent, uniform training of employees at
all banks. Consequently, David Desreumaux, VP of Human Resources, orders a
survey of mean employee training time in the Southeast region (population 1) and
the Southwest region (population 2). His staff randomly selected personnel
records of 81 employees from each region, and reported the following: x 1 = 30
hours, x 2 = 27 hours, S1 = 11, and S2 = 9. Assuming a two-tail test and  = .05,
the appropriate decision is _________________.
reject the alternate hypothesis 
do not reject the null hypothesis 
reject the null hypothesis 
do not reject the null hypothesis 
H
BCalc
A.
B.
C.
D.
C
Abel Alonozo, Director of Human Resources, is exploring employee absenteeism
at the Plano (population 1) and the Palestine (population 2) Piano Plants.
Previous studies indicate no difference in employee absenteeism at the two plants.
(The mean number of days absent per employee was the same at each plant.)
Abel plans to test this hypothesis using a random sample of 49 employees from
each plant. His null hypothesis is ____________.
15.




M
BApp
A.
B.
C.
D.
A
Abel Alonozo, Director of Human Resources, is exploring employee absenteeism
at the Plano (population 1) and the Palestine (population 2) Piano Plants.
Previous studies indicate no difference in employee absenteeism at the two plants.
(The mean number of days absent per employee was the same at each plant.)
Abel plans to test this hypothesis using a random sample of 49 employees from
each plant. His alternate hypothesis is ____________.
16.
M
BApp
A.
B.
C.
D.




Chapter 10: Statistical Inferences for Two Populations 309
D
17.
Abel Alonozo, Director of Human Resources, is exploring employee absenteeism
at the Plano (population 1) and the Palestine (population 2) Piano Plants.
Previous studies indicate no difference in employee absenteeism at the two plants.
(The mean number of days absent per employee was the same at each plant.) His
staff randomly selected personnel records of 49 employees from each plant, and
reported the following: x 1 = 7 days, x 2 = 8 days, S1 = 3, and S2 = 2. Assuming
a two-tail test and  = .01, the critical Z values are _________________.
M
BCalc
A.
B.
C.
D.
C
Abel Alonozo, Director of Human Resources, is exploring employee absenteeism
at the Plano (population 1) and the Palestine (population 2) Piano Plants.
Previous studies indicate no difference in employee absenteeism at the two plants.
(The mean number of days absent per employee was the same at each plant.) His
staff randomly selected personnel records of 49 employees from each plant, and
reported the following: x 1 = 7 days, x 2 = 8 days, S1 = 3, and S2 = 2. Assuming
a two-tail test and = .01, the calculated Z value is _________________.
18.
-1.64 and 1.64
-1.96 and 1.96
-2.33 and 2.33
-2.58 and 2.58
M
BCalc
A.
B.
C.
D.
A
Abel Alonozo, Director of Human Resources, is exploring employee absenteeism
at the Plano (population 1) and the Palestine (population 2) Piano Plants.
Previous studies indicate no difference in employee absenteeism at the two plants.
(The mean number of days absent per employee was the same at each plant.) His
staff randomly selected personnel records of 49 employees from each plant, and
reported the following: x 1 = 7 days, x 2 = 8 days, S1 = 3, and S2 = 2. Assuming
a two-tail test and  = .01, the appropriate decision is _________________.
19.
H
BCalc
A.
B.
C.
D.
-3.77
-3.13
-1.94
-9.80
do not reject the null hypothesis
reject the null hypothesis 
reject the null hypothesis 
do not reject the null hypothesis
310
Test Bank
B
20.
Abel Alonozo, Director of Human Resources, is exploring employee absenteeism
at the Plano (population 1) and the Palestine (population 2) Piano Plants.
Previous studies indicate no difference in employee absenteeism at the two plants.
(The mean number of days absent per employee was the same at each plant.) His
staff randomly selected personnel records of 49 employees from each plant, and
reported the following: x 1 = 7 days, x 2 = 8 days, S1 = 1, and S2 = 2. Assuming
a two-tail test and  = .01, the calculated Z value is _________________.
M
BCalc
A.
B.
C.
D.
C
Abel Alonozo, Director of Human Resources, is exploring employee absenteeism
at the Plano (population 1) and the Palestine (population 2) Piano Plants.
Previous studies indicate no difference in employee absenteeism at the two plants.
(The mean number of days absent per employee was the same at each plant.) His
staff randomly selected personnel records of 49 employees from each plant, and
reported the following: x 1 = 7 days, x 2 = 8 days, S1 = 1, and S2 = 2. Assuming
a two-tail test and  = .01, the appropriate decision is _________________.
21.
-16.33
-3.13
-9.80
-4.04
do not reject the null hypothesis
reject the null hypothesis 
reject the null hypothesis 
do not reject the null hypothesis
H
BCalc
A.
B.
C.
D.
A
Lucy Baker is analyzing demographic characteristics of two television programs,
COPS (population 1) and 60 Minutes (population 2). Previous studies indicate no
difference in the ages of the two audiences. (The mean age of each audience is
the same.) Lucy plans to test this hypothesis using a random sample of 100 from
each audience. Her null hypothesis is ____________.
22.
M
BApp
A.
B.
C.
D.




Chapter 10: Statistical Inferences for Two Populations 311
D
23.
Lucy Baker is analyzing demographic characteristics of two television programs,
COPS (population 1) and 60 Minutes (population 2). Previous studies indicate no
difference in the ages of the two audiences. (The mean age of each audience is
the same.) Lucy plans to test this hypothesis using a random sample of 100 from
each audience. Her alternate hypothesis is ____________.




M
BApp
A.
B.
C.
D.
B
Lucy Baker is analyzing demographic characteristics of two television programs,
COPS (population 1) and 60 Minutes (population 2). Previous studies indicate no
difference in the ages of the two audiences. (The mean age of each audience is
the same.) Her staff randomly selected 100 people from each audience, and
reported the following: x 1 = 43 years, x 2 = 45 years, S1 = 5, and S2 = 8.
Assuming a two-tail test and  = .05, the critical Z values are
_________________.
24.
M
BCalc
A.
B.
C.
D.
A
Lucy Baker is analyzing demographic characteristics of two television programs,
COPS (population 1) and 60 Minutes (population 2). Previous studies indicate no
difference in the ages of the two audiences. (The mean age of each audience is
the same.) Her staff randomly selected 100 people from each audience, and
reported the following: x 1 = 43 years, x 2 = 45 years, S1 = 5, and S2 = 8.
Assuming a two-tail test and  = .05, the calculated Z value is
_________________.
25.
M
BCalc
A.
B.
C.
D.
-1.64 and 1.64
-1.96 and 1.96
-2.33 and 2.33
-2.58 and 2.58
-2.12
-2.25
-5.58
-15.38
312
Test Bank
C
26.
Lucy Baker is analyzing demographic characteristics of two television programs,
COPS (population 1) and 60 Minutes (population 2). Previous studies indicate no
difference in the ages of the two audiences. (The mean age of each audience is
the same.) Her staff randomly selected 100 people from each audience, and
reported the following: x 1 = 43 years, x 2 = 45 years, S1 = 5, and S2 = 8.
Assuming a two-tail test and  = .05, the appropriate decision is
_________________.
do not reject the null hypothesis
reject the null hypothesis 
reject the null hypothesis 
do not reject the null hypothesis
H
BCalc
A.
B.
C.
D.
D
Lucy Baker is analyzing demographic characteristics of two television programs,
COPS (population 1) and 60 Minutes (population 2). Previous studies indicate no
difference in the ages of the two audiences. (The mean age of each audience is
the same.) Her staff randomly selected 100 people from each audience, and
reported the following: x 1 = 43 years, x 2 = 45 years, S1 = 8, and S2 = 8.
Assuming a two-tail test and  = .05, the calculated Z value is
_________________.
27.
M
BCalc
A.
B.
C.
D.
A
Lucy Baker is analyzing demographic characteristics of two television programs,
COPS (population 1) and 60 Minutes (population 2). Previous studies indicate no
difference in the ages of the two audiences. (The mean age of each audience is
the same.) Her staff randomly selected 100 people from each audience, and
reported the following: x 1 = 43 years, x 2 = 45 years, S1 = 8, and S2 = 8.
Assuming a two-tail test and  = .05, the appropriate decision is
_________________.
28.
H
BCalc
A.
B.
C.
D.
-12.50
-5.00
-1.56
-1.77
do not reject the null hypothesis
reject the null hypothesis 
reject the null hypothesis 
do not reject the null hypothesis
Chapter 10: Statistical Inferences for Two Populations 313
A
29.
M
Calc
B
A.
B.
C.
D.
30.
M
Calc
C
31.
M
Calc
0.4909
0.9909
0.0091
0.5091
Suppose that there is no difference in the population means of two populations.
Suppose also that the variance of the first population is 28 and the variance of the
second population is 30. A random sample of size 49 is drawn from the first
population and a random sample of size 36 is drawn from the second population.
Find the probability that the difference between the first sample mean and the
second sample mean is greater than 2.
A.
B.
C.
D.
32.
0.1190
0.3810
0.7200
0.3600
Assume that two independent random samples of size 100 each are taken from a
population that has a variance of 36. What is the probability that the difference in
the sample means is less than 2?
A.
B.
C.
D.
M
Calc
B
Assume that two independent random samples of size 100 each are taken from a
population that has a variance of 36. What is the probability that the difference in
the sample means is greater than 1?
0.4545
0.9545
0.0055
0.5055
Suppose that there is no difference in the population means of two populations.
Suppose also that the variance of the first population is 28 and the variance of the
second population is 30. A random sample of size 49 is drawn from the first
population and a random sample of size 36 is drawn from the second population.
Find the probability that the difference between the first sample mean and the
second sample mean is greater than 3.
A.
B.
C.
D.
0.4946
0.0054
0.9946
0.5054
314
Test Bank
A
33.
M
Calc
D
A.
B.
C.
D.
34.
M
Calc
A
M
Calc
Suppose that there is no difference in the population means of two populations.
Suppose also that the variance of the first population is 28 and the variance of the
second population is 30. A random sample of size 49 is drawn from the first
population and a random sample of size 36 is drawn from the second population.
What is the standard deviation for the sampling distribution of the differences in
sample means?
Suppose that there is no difference in the population means of two populations.
Suppose also that the standard deviation of the first population is 12 and the
standard deviation of the second population is 18. A random sample of size 64 is
drawn from the first population and a random sample of size 81 is drawn from the
second population. The sample mean of the sample from the first population is 90
and the sample mean of the sample from the second population is 84. What is the
standard deviation for the sampling distribution of the differences in sample
means?
A.
B.
C.
D.
35.
1.185
1.404
9
3
10.5
3.24
6.25
3.50
A researcher has a theory that the mean for population A is less than the mean for
population B. To test this, she randomly samples 36 items from population A and
determines that the sample average is 38.4 with a variance of 72. She randomly
samples 64 items from population B and determines that the sample average is
44.3 with a variance of 48.0. Alpha is .05. The calculated Z value is _______.
A.
B.
C.
D.
-3.56
-5.9
-.54
0.54
Chapter 10: Statistical Inferences for Two Populations 315
A
36.
To determine if there a difference in the average number years of experience of
assembly line employees between company A and company B, a researcher wants
to conduct a statistical test. He decides to conduct a two-tailed test. He selects an
alpha of .10. The critical value of Z for this problem is _______.
E
BCalc
A.
B.
C.
D.
D
To determine if there is a difference in the average number years of experience of
assembly line employees between company A and company B, a researcher wants
to conduct a statistical test. He decides to conduct a two-tailed test. He selects an
alpha of .10. He samples 100 employees of each firm. For company A,, the
sample mean is 7.0 and the standard deviation is 4. For company B, the sample
mean is 6.4 and the standard deviation is 3. The calculated Z for this problem is
_______.
37.
-1.645 and 1.645
1.96 and -1.96
1.28 and -1.28
1.28
M
BCalc
A.
B.
C.
D.
A
A researcher wants to estimate the difference in the means of two populations. A
random sample of 36 items from the first population results in a sample mean of
430 with a sample standard deviation of 120. A random sample of 49 items from
the second population results in a sample mean of 460 with a sample standard
deviation of 140. From this information, a point estimate of the difference of
population means can be computed as _______.
E
Calc
38.
A.
B.
C.
D.
-.12
0.12
0.6
1.2
-30
46
43
-13
316
Test Bank
B
39.
H
Calc
B
A.
B.
C.
D.
40.
H
Calc
C
H
Calc
A researcher wants to estimate the difference in the means of two populations. A
random sample of 36 items from the first population results in a sample mean of
430 with a sample standard deviation of 120. A random sample of 49 items from
the second population results in a sample mean of 460 with a sample standard
deviation of 140. From this information, a 95% confidence interval for the
difference in population means is _______.
A random sample of 36 items is taken from a population which has a population
variance of 144. The resulting sample mean is 45. A random sample of 36 items is
taken from a population which has a population variance of 121. The resulting
sample mean is 49. Using this information, compute a 98% confidence interval for
the difference in means of these two populations.
A.
B.
C.
D.
41.
-95.90 to 35.90
85.44 to 25.44
-76.53 to 16.53
-102.83 to 42.43
-10.99 to 2.99
-10.32 to 2.32
-8.46 to 0.46
-9.32 to 1.32
A researcher desires to estimate the difference in means of two populations. To
accomplish this, she takes a random sample of 81 items from the first population.
The sample yields a mean of 168 with a variance of 324. A random sample of 64
items is taken from the second population yielding a mean of 161 with a variance
of 625. Compute a 94% confidence interval for the difference in population
means.
A.
B.
C.
D.
3.51 to 10.49
1.25 to 12.75
0.02 to 13.98
-0.27 to 14.27
Chapter 10: Statistical Inferences for Two Populations 317
C
42.
M
Calc
B
A.
B.
C.
D.
43.
M
Calc
D
A researcher is interested in testing to determine if the mean of population one is
greater than the mean of population two. The null hypothesis is that there is no
difference in the population means (i.e. the difference is zero). The alternative
hypothesis is that there is a difference (i.e. the difference is not equal to zero). He
randomly selects a sample of 9 items from population one resulting in a mean of
14.3 and a standard deviation of 3.4. He randomly selects a sample of 14 items
from population two resulting in a mean of 11.8 and a standard deviation 2.9. He
is using an alpha value of .10 to conduct this test. The degrees of freedom for this
problem are _______.
A researcher is interested in testing to determine if the mean of population one is
greater than the mean of population two. The null hypothesis is that there is no
difference in the population means (i.e. the difference is zero). The alternative
hypothesis is that there is a difference (i.e. the difference is not equal to zero). He
randomly selects a sample of 9 items from population one resulting in a mean of
14.3 and a standard deviation of 3.4. He randomly selects a sample of 14 items
from population two resulting in a mean of 11.8 and a standard deviation 2.9. He
is using an alpha value of .10 to conduct this test. The critical t value from the
table is _______.
A.
B.
C.
D.
44.
E
Term
23
22
21
2
1.323
1.721
1.717
1.321
In testing a hypothesis about two population means, if the t distribution is used,
we must assume _______.
A.
B.
C.
D.
the sample sizes are equal
the population means are the same
the standard deviations are not the same
both populations are normally distributed
318
Test Bank
A
45.
E
Calc
C
A.
B.
C.
D.
46.
M
Calc
C
M
Calc
A researcher wishes to determine the difference in two population means. To do
this, she randomly samples 9 items from each population and computes a 90%
confidence interval. The sample from the first population produces a mean of 780
with a standard deviation of 240. The sample from the second population
produces a mean of 890 with a standard deviation of 280. Assume that the values
are normally distributed in each population. The point estimate for the difference
in the means of these two populations is _______.
A researcher wishes to determine the difference in two population means. To do
this, she randomly samples 9 items from each population and computes a 90%
confidence interval. The sample from the first population produces a mean of 780
with a standard deviation of 240. The sample from the second population
produces a mean of 890 with a standard deviation of 280. Assume that the values
are normally distributed in each population. The t value used for this is _______.
A.
B.
C.
D.
47.
-110
40
-40
0
1.860
1.734
1.746
1.337
A researcher wishes to determine the difference in two population means. To do
this, she randomly samples 9 items from each population and computes a 90%
confidence interval. The sample from the first population produces a mean of 780
with a standard deviation of 240. The sample from the second population
produces a mean of 890 with a standard deviation of 280. Assume that the values
are normally distributed in each population. The degrees of freedom for this are
_______.
A.
B.
C.
D.
8
17
16
7
Chapter 10: Statistical Inferences for Two Populations 319
B
48.
The matched-pairs t test deals with _______.
E
Term
A.
B.
C.
D.
B
A researcher wants to conduct a before/after study on 11 subjects to determine if a
treatment results in any difference in scores. The null hypothesis is that the
average difference is zero while the alternative hypothesis is that the average
difference is not zero. Scores are obtained on the subjects both before and after
the treatment. After subtracting the after scores from the before scores, the
average difference is computed to be -2.40 with a sample standard deviation of
1.21. The degrees of freedom for this test are _______.
49.
E
Calc
B
M
Calc
A.
B.
C.
D.
50.
independent samples
related samples
large samples
dating service questionnaires
11
10
9
20
A researcher wants to conduct a before/after study on 11 subjects to determine if a
treatment results in any difference in scores. The null hypothesis is that the
average difference is zero while the alternative hypothesis is that the average
difference is not zero. Scores are obtained on the subjects both before and after
the treatment. After subtracting the after scores from the before scores, the
average difference is computed to be -2.40 with a sample standard deviation of
1.21. The computed t value for this test is _______.
A.
B.
C.
D.
-21.82
-6.58
-2.4
1.98
320
Test Bank
B
51.
M
Calc
A
A.
B.
C.
D.
52.
M
Calc
A
M
Calc
A researcher wants to conduct a before/after study on 11 subjects to determine if a
treatment results in any difference in scores. The null hypothesis is that the
average difference is zero while the alternative hypothesis is that the average
difference is not zero. Scores are obtained on the subjects both before and after
the treatment. After subtracting the after scores from the before scores, the
average difference is computed to be -2.40 with a sample standard deviation of
1.21. A 0.05 level of significance is selected. The table t value for this test is
_______.
A researcher is performing a two-tailed related samples (matched pairs) t-test. A
total of 12 people are in the sample, and before and after measures are taken. The
computed t value for this is -1.84. The level of significance is 0.05. The correct
decision is to _______.
A.
B.
C.
D.
53.
1.812
2.228
2.086
2.262
do not reject the null hypothesis
reject the null hypothesis
take a larger sample
use the Z table instead of the t table
A researcher is performing a two-tailed related samples (matched pairs) t-test. A
total of 8 people are in the sample, and before and after measures are taken. The
computed t value for this is -1.97. The level of significance is 0.10. The correct
decision is to _______.
A.
B.
C.
D.
do not reject the null hypothesis
reject the null hypothesis
take a larger sample
use the Z table instead of the t table
Chapter 10: Statistical Inferences for Two Populations 321
B
54.
Assume that the data are normally distributed in the population. The sample
standard deviation (S) is _______.
A. 1.3
B. 1.14
C. 1.04
D. 1.02
M
Calc
A
E
Calc
A researcher is conducting a matched-pairs study. She gathers data on each pair in
the study resulting in:
Pair
Group 1
Group 2
1
10
12
2
8
9
3
11
11
4
8
10
5
9
12
55.
A researcher is conducting a matched-pairs study. She gathers data on each pair in
the study resulting in:
Pair
Group 1
Group 2
1
10
12
2
8
9
3
11
11
4
8
10
5
9
12
Assume that the data are normally distributed in the population. The degrees of
freedom in this problem are _______.
A. 4
B. 8
C. 5
D. 9
322
Test Bank
B
56.
A researcher is conducting a matched-pairs study. She gathers data on each pair in
the study resulting in:
Pair
Group 1
Group 2
1
10
12
2
8
9
3
11
11
4
8
10
5
9
12
Assume that the data are normally distributed in the population. The level of
significance is selected to be 0.10. If a two-tailed test is performed, the null
hypothesis would be rejected if the calculated value of t is _______.
M
Calc
A
A.
B.
C.
D.
57.
less than -1.533 or greater than 1.533
less than -2.132 or greater than 2.132
less than -2.776 or greater than 2.776
less than -1.860 or greater than 1.860
A researcher is conducting a matched-pairs study. She gathers data on each pair in
the study resulting in:
Pair
Group 1
Group 2
1
10
12
2
8
9
3
11
11
4
8
10
5
9
12
Assume that the data are normally distributed in the population. The level of
significance is selected to be 0.10. If the alternative hypothesis is that the average
difference is greater than zero, the null hypothesis would be rejected if the
calculated value of t is _______.
M
Calc
A.
B.
C.
D.
greater than 1.533
less than -1.533
greater than 2.132
less than -2.132
Chapter 10: Statistical Inferences for Two Populations 323
D
58.
A researcher is estimating the average difference between two population means
based on matched-pairs samples. She gathers data on each pair in the study
resulting in:
Pair
Group 1
Group 2
1
10
12
2
8
9
3
11
11
4
8
10
5
9
12
Assume that the data are normally distributed in the population. To obtain a 95%
confidence interval, the table t value would be _______.
M
Calc
D
A.
B.
C.
D.
59.
2.132
1.86
2.306
2.776
A researcher is estimating the average difference between two population means
based on matched-pairs samples. She gathers data on each pair in the study
resulting in:
Pair
Group 1
Group 2
1
10
12
2
8
9
3
11
11
4
8
10
5
9
12
Assume that the data are normally distributed in the population. To obtain a 90%
confidence interval, the table t value would be _______.
M
Calc
A.
B.
C.
D.
1.86
1.397
1.533
2.132
324
Test Bank
A
60.
A researcher is estimating the average difference between two population means
based on matched-pairs samples. She gathers data on each pair in the study
resulting in:
Pair
Group 1
Group 2
1
10
12
2
8
9
3
11
11
4
8
10
5
9
12
Assume that the data are normally distributed in the population. A 95%
confidence interval would be _______.
H
Calc
D
A.
B.
C.
D.
61.
M
BApp
-3.02 to -0.18
-1.6 to -1.09
-2.11 to 1.09
-2.11 to -1.09
Michael Fugate, Marketing Manager at Classic Merchandise, is investigating
response rates to scented and unscented direct mail catalogs. If the response rate
for the scented catalog (population 1) is higher, Mike will adopt the scented
version. His staff randomly selects two samples of 200 each from the company’s
customer database. One month after the 400 test catalogs were mailed, forty-five
orders (twenty-five from the scented and twenty from the unscented) were
received from the test catalogs. Assuming  = .01, Mike’s null hypothesis is
________________.
A.
B.
C.
D.
1 < 2
1 = 2
1  2
P1  P 2
Chapter 10: Statistical Inferences for Two Populations 325
A
62.
Michael Fugate, Marketing Manager at Classic Merchandise, is investigating
response rates to scented and unscented direct mail catalogs. If the response rate
for the scented catalog (population 1) is higher, Mike will adopt the scented
version. His staff randomly selects two samples of 200 each from the company’s
customer database. One month after the 400 test catalogs were mailed, forty-five
orders (twenty-five from the scented and twenty from the unscented) were
received from the test catalogs. Assuming  = .01, Mike’s alternate hypothesis is
________________.
M
BApp
A.
B.
C.
D.
B
Michael Fugate, Marketing Manager at Classic Merchandise, is investigating
response rates to scented and unscented direct mail catalogs. If the response rate
for the scented catalog (population 1) is higher, Mike will adopt the scented
version. His staff randomly selects two samples of 200 each from the company’s
customer database. One month after the 400 test catalogs were mailed, forty-five
orders (twenty-five from the scented and twenty from the unscented) were
received from the test catalogs. Assuming  = .01, the critical Z value is
________________.
63.
P1 > P 2
1 = 2
1  2
1  2
M
BApp
A.
B.
C.
D.
C
Michael Fugate, Marketing Manager at Classic Merchandise, is investigating
response rates to scented and unscented direct mail catalogs. If the response rate
for the scented catalog (population 1) is higher, Mike will adopt the scented
version. His staff randomly selects two samples of 200 each from the company’s
customer database. One month after the 400 test catalogs were mailed, forty-five
orders (twenty-five from the scented and twenty from the unscented) were
received from the test catalogs. Assuming  = .01, the calculated Z value is
________________.
64.
M
BApp
A.
B.
C.
D.
-1.645
2.33
1.96
2.58
0.0316
0.1000
0.7912
0.1250
326
Test Bank
C
65.
Michael Fugate, Marketing Manager at Classic Merchandise, is investigating
response rates to scented and unscented direct mail catalogs. If the response rate
for the scented catalog (population 1) is higher, Mike will adopt the scented
version. His staff randomly selects two samples of 200 each from the company’s
customer database. One month after the 400 test catalogs were mailed, forty-five
orders (twenty-five from the scented and twenty from the unscented) were
received from the test catalogs. Assuming  = .01, the appropriate decision is
________________.
do not reject the null hypothesis 1 = 2
reject the null hypothesis P1 > P2
do not reject the null hypothesis P1  P2
reject the null hypothesis P1  P2
H
BCalc
A.
B.
C.
D.
B
Michael Fugate, Marketing Manager at Classic Merchandise, is investigating
response rates to scented and unscented direct mail catalogs. If the response rate
for the scented catalog (population 1) is higher, Mike will adopt the scented
version. His staff randomly selects two samples of 200 each from the company’s
customer database. One month after the 400 test catalogs were mailed, fifty-four
orders (thirty-six from the scented and eighteen from the unscented) were received
from the test catalogs. Assuming  = .01, the calculated Z value is __________.
66.
M
BApp
A.
B.
C.
D.
D
Michael Fugate, Marketing Manager at Classic Merchandise, is investigating
response rates to scented and unscented direct mail catalogs. If the response rate
for the scented catalog (population 1) is higher, Mike will adopt the scented
version. His staff randomly selects two samples of 200 each from the company’s
customer database. One month after the 400 test catalogs were mailed, fifty-four
orders (thirty-five from the scented and eighteen from the unscented) were
received from the test catalogs. Assuming  = .01, the appropriate decision is
________________.
67.
H
BCalc
A.
B.
C.
D.
1.96
2.63
-1.96
3.19
do not reject the null hypothesis 1 = 2
reject the null hypothesis P1 > P2
do not reject the null hypothesis P1  P2
reject the null hypothesis P1  P2
Chapter 10: Statistical Inferences for Two Populations 327
C
68.
Catherine Chao, Director of Marketing Research, is evaluating consumer
acceptance of a new toothpaste package. She hypothesizes that the acceptance
rate will be identical in all U.S. markets. Her staff randomly selects a sample of
200 households in Kansas City (population 1) and a sample of 300 households in
Seattle (population 2). Forty of the Kansas City households prefer the new
package to all other package designs, as did eighty-one of the Seattle households.
Assuming  = .05, Catherine's null hypothesis is ______________.
1 < 2
1 = 2
P1 = P2
1 2
E
BApp
A.
B.
C.
D.
D
Catherine Chao, Director of Marketing Research, is evaluating consumer
acceptance of a new toothpaste package. She hypothesizes that the acceptance
rate will be identical in all U.S. markets. Her staff randomly selects a sample of
200 households in Kansas City (population 1) and a sample of 300 households in
Seattle (population 2). Forty of the Kansas City households prefer the new
package to all other package designs, as did eighty-one of the Seattle households.
Assuming  = .05, Catherine's alternate hypothesis is ______________.
69.
E
BApp
A. 1 2
B. 1 2
C. 1 < 2
D. P1 P2
A
Catherine Chao, Director of Marketing Research, is evaluating consumer
acceptance of a new toothpaste package. She hypothesizes that the acceptance
rate will be identical in all U.S. markets. Her staff randomly selects a sample of
200 households in Kansas City (population 1) and a sample of 300 households in
Seattle (population 2). Forty of the Kansas City households prefer the new
package to all other package designs, as did eighty-one of the Seattle households.
Assuming  = .05, the critical Z values are ______________.
70.
E
BCalc
A.
B.
C.
D.
-1.96 and 1.96
-1.64 and 1.64
-2.58 and 2.58
-2.33 and 2.33
328
Test Bank
B
71.
Catherine Chao, Director of Marketing Research, is evaluating consumer
acceptance of a new toothpaste package. She hypothesizes that the acceptance
rate will be identical in all U.S. markets. Her staff randomly selects a sample of
200 households in Kansas City (population 1) and a sample of 300 households in
Seattle (population 2). Forty of the Kansas City households prefer the new
package to all other package designs, as did eighty-one of the Seattle households.
Assuming  = .05, the calculated Z value is ______________.
M
BCalc
A.
B.
C.
D.
C
Catherine Chao, Director of Marketing Research, is evaluating consumer
acceptance of a new toothpaste package. She hypothesizes that the acceptance
rate will be identical in all U.S. markets. Her staff randomly selects a sample of
200 households in Kansas City (population 1) and a sample of 300 households in
Seattle (population 2). Forty of the Kansas City households prefer the new
package to all other package designs, as did eighty-one of the Seattle households.
Assuming  = .05, the appropriate decision is ______________.
72.
2.48
-1.79
-3.13
1.54
do not reject the null hypothesis 1 = 2
reject the null hypothesis 1 = 2
do not reject the null hypothesis P1 = P2
reject the null hypothesis P1 = P2
H
BCalc
A.
B.
C.
D.
A
Catherine Chao, Director of Marketing Research, is evaluating consumer
acceptance of a new toothpaste package. She hypothesizes that the acceptance
rate will be identical in all U.S. markets. Her staff randomly selects a sample of
200 households in Kansas City (population 1) and a sample of 300 households in
Seattle (population 2). Seventy-five of the Kansas City households prefer the new
package to all other package designs, as did eighty-one of the Seattle households.
Assuming  = .05, the calculated Z value is ______________.
73.
M
BCalc
A.
B.
C.
D.
2.48
-1.79
-3.13
1.54
Chapter 10: Statistical Inferences for Two Populations 329
D
74.
Catherine Chao, Director of Marketing Research, is evaluating consumer
acceptance of a new toothpaste package. She hypothesizes that the acceptance
rate will be identical in all U.S. markets. Her staff randomly selects a sample of
200 households in Kansas City (population 1) and a sample of 300 households in
Seattle (population 2). Seventy-five of the Kansas City households prefer the new
package to all other package designs, as did eighty-one of the Seattle households.
Assuming  = .05, the appropriate decision is ______________.
do not reject the null hypothesis 1 = 2
reject the null hypothesis 1 = 2
do not reject the null hypothesis P1 = P2
reject the null hypothesis P1 = P2
H
BCalc
A.
B.
C.
D.
A
Maureen McIlvoy, owner and CEO of a mail order business for wind surfing
equipment and supplies, is reviewing the order filling operations at her
warehouses. Her goal is 100% of orders shipped within 24 hours. In previous
years, neither warehouse has achieved the goal, but the East Coast Warehouse has
consistently out-performed the West Coast Warehouse. Her staff randomly
selected 200 orders from the West Coast Warehouse (population 1) and 400
orders from the East Coast Warehouse (population 2), and reports that 190 of the
West Coast Orders were shipped within 24 hours, and the East Coast Warehouse
shipped 372 orders within 24 hours. Maureen's null hypothesis is __________.
75.
E
BApp
A.
B.
C.
D.
P1  P 2
1 = 2
P1 = P2
1 2
330
Test Bank
C
76.
Maureen McIlvoy, owner and CEO of a mail order business for wind surfing
equipment and supplies, is reviewing the order filling operations at her
warehouses. Her goal is 100% of orders shipped within 24 hours. In previous
years, neither warehouse has achieved the goal, but the East Coast Warehouse has
consistently out-performed the West Coast Warehouse. Her staff randomly
selected 200 orders from the West Coast Warehouse (population 1) and 400
orders from the East Coast Warehouse (population 2), and reports that 190 of the
West Coast Orders were shipped within 24 hours, and the East Coast Warehouse
shipped 372 orders within 24 hours. Maureen's alternate hypothesis is _______.
P1  P 2
1 > 2
P1 > P2
1  2
E
BApp
A.
B.
C.
D.
C
Maureen McIlvoy, owner and CEO of a mail order business for wind surfing
equipment and supplies, is reviewing the order filling operations at her
warehouses. Her goal is 100% of orders shipped within 24 hours. In previous
years, neither warehouse has achieved the goal, but the East Coast Warehouse has
consistently out-performed the West Coast Warehouse. Her staff randomly
selected 200 orders from the West Coast Warehouse (population 1) and 400
orders from the East Coast Warehouse (population 2), and reports that 190 of the
West Coast Orders were shipped within 24 hours, and the East Coast Warehouse
shipped 372 orders within 24 hours. Assuming  = 0.05, the critical Z value is
___________________.
77.
M
BCalc
A.
B.
C.
D.
-1.96
-1.64
1.64
1.96
Chapter 10: Statistical Inferences for Two Populations 331
D
78.
Maureen McIlvoy, owner and CEO of a mail order business for wind surfing
equipment and supplies, is reviewing the order filling operations at her
warehouses. Her goal is 100% of orders shipped within 24 hours. In previous
years, neither warehouse has achieved the goal, but the East Coast Warehouse has
consistently out-performed the West Coast Warehouse. Her staff randomly
selected 200 orders from the West Coast Warehouse (population 1) and 400
orders from the East Coast Warehouse (population 2), and reports that 190 of the
West Coast Orders were shipped within 24 hours, and the East Coast Warehouse
shipped 372 orders within 24 hours. Assuming  = 0.05, the calculated Z value is
___________________.
M
BCalc
A.
B.
C.
D.
B
Maureen McIlvoy, owner and CEO of a mail order business for wind surfing
equipment and supplies, is reviewing the order filling operations at her
warehouses. Her goal is 100% of orders shipped within 24 hours. In previous
years, neither warehouse has achieved the goal, but the East Coast Warehouse has
consistently out-performed the West Coast Warehouse. Her staff randomly
selected 200 orders from the West Coast Warehouse (population 1) and 400
orders from the East Coast Warehouse (population 2), and reports that 190 of the
West Coast Orders were shipped within 24 hours, and the East Coast Warehouse
shipped 372 orders within 24 hours. Assuming  = 0.05, the appropriate decision
is ___________________.
79.
H
BCalc
A.
B.
C.
D.
-3.15
2.42
1.53
0.95
do not reject the null hypothesis 1  2
do not reject the null hypothesis P1  P2
reject the null hypothesis 1 = 2
reject the null hypothesis P1 = P2
332
Test Bank
B
80.
Maureen McIlvoy, owner and CEO of a mail order business for wind surfing
equipment and supplies, is reviewing the order filling operations at her
warehouses. Her goal is 100% of orders shipped within 24 hours. In previous
years, neither warehouse has achieved the goal, but the East Coast Warehouse has
consistently out-performed the West Coast Warehouse. Her staff randomly
selected 200 orders from the West Coast Warehouse (population 1) and 400
orders from the East Coast Warehouse (population 2), and reports that 190 of the
West Coast Orders were shipped within 24 hours, and the East Coast Warehouse
shipped 356 orders within 24 hours. Assuming = 0.05, the calculated Z value is
___________________.
M
BCalc
A.
B.
C.
D.
A
Maureen McIlvoy, owner and CEO of a mail order business for wind surfing
equipment and supplies, is reviewing the order filling operations at her
warehouses. Her goal is 100% of orders shipped within 24 hours. In previous
years, neither warehouse has achieved the goal, but the East Coast Warehouse has
consistently out-performed the West Coast Warehouse. Her staff randomly
selected 200 orders from the West Coast Warehouse (population 1) and 400
orders from the East Coast Warehouse (population 2), and reports that 190 of the
West Coast Orders were shipped within 24 hours, and the East Coast Warehouse
shipped 356 orders within 24 hours. Assuming = 0.05, the appropriate decision
is ___________________.
81.
-3.15
2.42
1.53
0.95
reject the null hypothesis P1  P2
reject the null hypothesis 1 2
do not reject the null hypothesis 1 = 2
do not reject the null hypothesis P1 = P2
H
BCalc
A.
B.
C.
D.
C
Suppose that .06 of each of two populations possess a given characteristic.
Samples of size 400 are randomly drawn from each population. The probability
that the difference between the first sample proportion which possess the given
characteristic and the second sample proportion which possess the given
characteristic being more than +.03 is _______.
M
Calc
82.
A.
B.
C.
D.
0.4943
0.9943
0.0057
0.5057
Chapter 10: Statistical Inferences for Two Populations 333
B
83.
M
Calc
C
A.
B.
C.
D.
84.
M
Calc
D
85.
M
Term
0.4535
0.9535
0.0465
0.5465
A statistician is being asked to test a new theory that the proportion of population
A possessing a given characteristic is greater than the proportion of population B
possessing the characteristic. A random sample of 600 from population A has
been taken and it is determined that 480 possess the characteristic. A random
sample of 700 taken from population B results in 350 possessing the
characteristic. The calculated Z for this is _______.
A.
B.
C.
D.
86.
0.00300
0.01200
0.05640
0.00014
Suppose that .06 of each of two populations possess a given characteristic.
Samples of size 400 are randomly drawn from each population. What is the
probability that the differences in sample proportions will be greater than 0.02?
A.
B.
C.
D.
M
Calc
A
Suppose that .06 of each of two populations possess a given characteristic.
Samples of size 400 are randomly drawn from each population. The standard
deviation for the sampling distribution of differences between the first sample
proportion and the second sample proportion (used to calculate the Z score) is
_______.
0.300
0.624
0.638
11.22
If you are testing a hypothesis that two population proportions are the same, you
_______.
A.
B.
C.
D.
should calculate a "pooled" value for the sample proportion
should not calculate a "pooled" value for the sample proportion
use a sample proportion of zero
always use a 0.05 level of significance
334
Test Bank
A
87.
E
Calc
B
A.
B.
C.
D.
88.
M
Calc
D
M
Calc
A researcher is interested in estimating the difference in two population
proportions. A sample of 400 from each population results in sample proportions
of .61 and .64. The point estimate of the difference in the population proportions
is _______.
A researcher is interested in estimating the difference in two population
proportions. A sample of 400 from each population results in sample proportions
of .61 and .64. A 90% confidence interval for the difference in the population
proportions is _______.
A.
B.
C.
D.
89.
-0.03
0.625
0
0.400
-0.10 to 0.04
-0.09 to 0.03
-0.11 to 0.05
-0.07 to 0.01
A random sample of 400 items from a population shows that 160 of the sample
items possess a given characteristic. A random sample of 400 items from a second
population resulted in 110 of the sample items possessing the characteristic. Using
this data, a 99% confidence interval is constructed to estimate the difference in
population proportions which possess the given characteristic. The resulting
confidence interval is _______.
A.
B.
C.
D.
0.06 to 0.19
0.05 to 0.22
0.09 to 0.16
0.04 to 0.21
Chapter 10: Statistical Inferences for Two Populations 335
A
90.
E
BApp
Collinsville Construction Company purchases steel rods for its projects. Based on
previous tests, Claude Carter, Quality Assurance Manager, has recommended
purchasing rods from Redding Rods, Inc. (population 1), rather than Stockton
Steel (population 2), since Redding's rods had less variability in length. Recently,
Stockton revised it rod shearing operation, and Claude has sampled the outputs
from Redding's and Stockton's rod manufacturing processes. The results for
2
2
Redding were S1 = 0.10 with n1 = 8, and, for Stockton, the results were S2 =
0.05 with n2 = 10. Claude's null hypothesis is __________________.
A. 1  2
2
2
B. 2  1
2
2
C. 1  2
2
2
D. 2  1
2
C
91.
E
BApp
2
Collinsville Construction Company purchases steel rods for its projects. Based on
previous tests, Claude Carter, Quality Assurance Manager, has recommended
purchasing rods from Redding Rods, Inc. (population 1), rather than Stockton
Steel (population 2), since Redding's rods had less variability in length. Recently,
Stockton revised it rod shearing operation, and Claude has sampled the outputs
from Redding's and Stockton's rod manufacturing processes. The results for
2
2
Redding were S1 = 0.10 with n1 = 8, and, for Stockton, the results were S2 =
0.05 with n2 = 10. Claude's alternate hypothesis is __________________.
A. 1  2
2
2
B. 2  1
2
2
C. 1  2
2
2
D. 2  1
2
2
336
Test Bank
B
92.
Collinsville Construction Company purchases steel rods for its projects. Based on
previous tests, Claude Carter, Quality Assurance Manager, has recommended
purchasing rods from Redding Rods, Inc. (population 1), rather than Stockton
Steel (population 2), since Redding's rods had less variability in length. Recently,
Stockton revised it rod shearing operation, and Claude has sampled the outputs
from Redding's and Stockton's rod manufacturing processes. The results for
2
2
Redding were S1 = 0.10 with n1 = 8, and, for Stockton, the results were S2 =
0.05 with n2 = 10. Assuming  = 0.05, the critical F value is
__________________.
E
BCalc
A.
B.
C.
D.
B
Collinsville Construction Company purchases steel rods for its projects. Based on
previous tests, Claude Carter, Quality Assurance Manager, has recommended
purchasing rods from Redding Rods, Inc. (population 1), rather than Stockton
Steel (population 2), since Redding's rods had less variability in length. Recently,
Stockton revised it rod shearing operation, and Claude has sampled the outputs
from Redding's and Stockton's rod manufacturing processes. The results for
2
2
Redding were S1 = 0.10 with n1 = 8, and, for Stockton, the results were S2 =
0.05 with n2 = 10. Assuming = 0.05, the calculated F value is
__________________.
93.
M
BCalc
A.
B.
C.
D.
3.68
3.29
3.50
3.79
0.50
2.00
1.41
0.71
Chapter 10: Statistical Inferences for Two Populations 337
D
94.
H
BCalc
D
95.
M
BCalc
Collinsville Construction Company purchases steel rods for its projects. Based on
previous tests, Claude Carter, Quality Assurance Manager, has recommended
purchasing rods from Redding Rods, Inc. (population 1), rather than Stockton
Steel (population 2), since Redding's rods had less variability in length. Recently,
Stockton revised it rod shearing operation, and Claude has sampled the outputs
from Redding's and Stockton's rod manufacturing processes. The results for
2
2
Redding were S1 = 0.10 with n1 = 8, and, for Stockton, the results were S2 =
0.05 with n2 = 10. Assuming = 0.05, the appropriate decision is
__________________.
A. reject the null hypothesis 1  2
2
2
B. reject the null hypothesis 2  1
2
2
C. do not reject the null hypothesis 2  1
2
2
D. do not reject the null hypothesis 1  2
2
2
Collinsville Construction Company purchases steel rods for its projects. Based on
previous tests, Claude Carter, Quality Assurance Manager, has recommended
purchasing rods from Redding Rods, Inc. (population 1), rather than Stockton
Steel (population 2), since Redding's rods had less variability in length. Recently,
Stockton revised it rod shearing operation, and Claude has sampled the outputs
from Redding's and Stockton's rod manufacturing processes. The results for
2
2
Redding were S1 = 0.15 with n1 = 8, and, for Stockton, the results were S2 =
0.04 with n2 = 10. Assuming = 0.05, the calculated F value is
__________________.
A.
B.
C.
D.
0.27
0.52
1.92
3.75
338
Test Bank
B
96.
H
BCalc
Collinsville Construction Company purchases steel rods for its projects. Based on
previous tests, Claude Carter, Quality Assurance Manager, has recommended
purchasing rods from Redding Rods, Inc. (population 1), rather than Stockton
Steel (population 2), since Redding's rods had less variability in length. Recently,
Stockton revised it rod shearing operation, and Claude has sampled the outputs
from Redding's and Stockton's rod manufacturing processes. The results for
2
2
Redding were S1 = 0.15 with n1 = 8, and, for Stockton, the results were S2 =
0.05 with n2 = 10. Assuming = 0.04, the appropriate decision is
__________________.
A. reject the null hypothesis 2  1
2
2
B. reject the null hypothesis 1  2
2
2
C. do not reject the null hypothesis 1  2
2
2
D. do not reject the null hypothesis 2  1
2
C
97.
2
Tamara Hill, fund manager of the Hill Value Fund, manages a portfolio of 250
common stocks. Tamara is searching for a 'low risk' issue to add to the portfolio,
i.e., one with a price variance less than that of the S&P 500 index. Moreover, she
assumes an issue is not 'low risk' until demonstrated otherwise. Her staff reported
that during the last nine quarters the price variance for the S&P 500 index
(population 1) was 25, and for the last seven quarters the price variance for XYC
common (population 2) was 8. Using= 0.05, Tamara's null hypothesis is
_______.
E
A.
BApp
B.
C.
D.
 
 
 
 
2
1
2
2
2
1
2
2
2
2
2
1
2
2
2
1
Chapter 10: Statistical Inferences for Two Populations 339
A
98.
E
Tamara Hill, fund manager of the Hill Value Fund, manages a portfolio of 250
common stocks. Tamara is searching for a 'low risk' issue to add to the portfolio,
i.e., one with a price variance less than that of the S&P 500 index. Moreover, she
assumes an issue is not 'low risk' until demonstrated otherwise. Her staff reported
that during the last nine quarters the price variance for the S&P 500 index
(population 1) was 25, and for the last seven quarters the price variance for XYC
common (population 2) was 8. Using = 0.05, Tamara's alternate hypothesis is
_______.
A.
BApp
B.
C.
D.
C
99.
  
 
 
 
2
1
2
2
2
1
2
2
2
2
2
1
2
2
2
1
Tamara Hill, fund manager of the Hill Value Fund, manages a portfolio of 250
common stocks. Tamara is searching for a 'low risk' issue to add to the portfolio,
i.e., one with a price variance less than that of the S&P 500 index. Moreover, she
assumes an issue is not 'low risk' until demonstrated otherwise. Her staff reported
that during the last nine quarters the price variance for the S&P 500 index
(population 1) was 25, and for the last seven quarters the price variance for XYC
common (population 2) was 8. Using = 0.05, the critical F value is _______.
E
BCalc
A.
B.
C.
D.
3.68
3.58
4.15
3.29
A 100.
Tamara Hill, fund manager of the Hill Value Fund, manages a portfolio of 250
common stocks. Tamara is searching for a 'low risk' issue to add to the portfolio,
i.e., one with a price variance less than that of the S&P 500 index. Moreover, she
assumes an issue is not 'low risk' until demonstrated otherwise. Her staff reported
that during the last nine quarters the price variance for the S&P 500 index
(population 1) was 25, and for the last seven quarters the price variance for XYC
common (population 2) was 8. Using = 0.05, the calculated F value is _______.
M
BCalc
A.
B.
C.
D.
3.13
0.32
1.77
9.77
340
Test Bank
D 101.
H
BCalc
Tamara Hill, fund manager of the Hill Value Fund, manages a portfolio of 250
common stocks. Tamara is searching for a 'low risk' issue to add to the portfolio,
i.e., one with a price variance less than that of the S&P 500 index. Moreover, she
assumes an issue is not 'low risk' until demonstrated otherwise. Her staff reported
that during the last nine quarters the price variance for the S&P 500 index
(population 1) was 25, and for the last seven quarters the price variance for XYC
common (population 2) was 8. Using = 0.05, the appropriate decision is
_______.
A. reject the null hypothesis 1  2
2
2
B. reject the null hypothesis 2  1
2
2
C. do not reject the null hypothesis 2  1
2
2
D. do not reject the null hypothesis 1  2
2
2
D 102.
Tamara Hill, fund manager of the Hill Value Fund, manages a portfolio of 250
common stocks. Tamara is searching for a 'low risk' issue to add to the portfolio,
i.e., one with a price variance less than that of the S&P 500 index. Moreover, she
assumes an issue is not 'low risk' until demonstrated otherwise. Her staff reported
that during the last nine quarters the price variance for the S&P 500 index
(population 1) was 25, and for the last seven quarters the price variance for XYC
common (population 2) was 6. Using = 0.05, the calculated F value is _______.
M
BCalc
A.
B.
C.
D.
B 103.
Tamara Hill, fund manager of the Hill Value Fund, manages a portfolio of 250
common stocks. Tamara is searching for a 'low risk' issue to add to the portfolio,
i.e., one with a price variance less than that of the S&P 500 index. Moreover, she
assumes an issue is not 'low risk' until demonstrated otherwise. Her staff reported
that during the last nine quarters the price variance for the S&P 500 index
(population 1) was 25, and for the last seven quarters the price variance for XYC
common (population 2) was 6. Using = 0.05, the appropriate decision is
_______.
H
A. reject the null hypothesis
BCalc
B.
17.36
2.04
0.24
4.17

reject the null hypothesis 
2
2
2
1
  1
2
  2
2
C. do not reject the null hypothesis  1   2
2
2
D. do not reject the null hypothesis  2   1
2
2
Chapter 10: Statistical Inferences for Two Populations 341
104.
M
BApp
Discrete Components, Inc. (DCI) manufactures a line of electrical resistors which
it sells to a variety of customers -- equipment manufacturers and electrical parts
wholesaler, for example. Yvonne Yang, VP of Finance, is reviewing DCI's
current policy of extending the same credit terms and applying identical collection
procedures to all credit customers. Yvonne feels that credit terms and collection
policies should be designed for various categories of customers. She has access to
an extensive data base of credit applications and to the purchase/payment history
of DCI's credit customers.
Discuss how Yvonne can use inferential statistics to explore differences between
various populations of credit customers. Identify several populations for the
study, and suggest methods of comparing them.
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
342
Test Bank
105.
M
BApp
Quinton Quayle is VP of Human Resources for Lone Oak Hospitals which
operates a national chain of rehabilitation hospitals. Lone Oak employees a
variety of health-care professionals including doctors, nurses, pharmacists, and
physical therapists in various geographical and urban/suburb settings. Quinton is
reviewing Lone Oak's employee compensation plans and feels that a
compensation plan should be defined for each employee population.
Discuss how Quinton can use inferential statistics to explore differences between
various populations of professional employees. Identify several populations
(other than the professions list above) for the study, and suggest methods of
comparing them.
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
Chapter 10: Statistical Inferences for Two Populations 343
106.
Lucy Baker is analyzing demographic characteristics of two television programs –
Lawrence Welk Show and Wild Discovery. Her staff analyzed the age of audience
menbers and produced the following table using Excel.
Lawrence Welk Discovery
Mean
Standard Error
Median
Mode
Standard Deviation
Sample Variance
Kurtosis
Skewness
Range
Minimum
Maximum
Sum
Count
Confidence Level(95.0%)
44.64197531
1.111015085
46
54
9.999135765
99.98271605
-0.676289934
-0.279781108
42
21
63
3616
81
2.210992632
34.98765
0.519524
35
35
4.675719
21.86235
0.063433
-0.09582
24
22
46
2834
81
1.033887
What sample sizes were used? Is there a staticstically significant difference in the
average age of the two audiences?
Discuss how Lucy can use inferential statistics to explore differences between
various populations of television audiences.
M
BApp
344
Test Bank
107.
Lucy Baker is analyzing demographic characteristics of two television programs –
Lawrence Welk Show and Wild Discovery. Her staff analyzed the age of audience
menbers and produced the following table using MINITAB.
Two Sample T-Test and Confidence Interval
Two sample T for Lawrence Welk vs Discovery
Lawrence
Discover
N
81
81
Mean
44.6
34.99
StDev
10.0
4.68
SE Mean
1.1
0.52
95% CI for mu Lawrence - mu Discover: ( 7.2, 12.08)
T-Test mu Lawrence = mu Discover (vs <): T = 7.87 P = 1.0
DF = 113
What sample sizes were used? Is there a staticstically significant difference in the
average age of the two audiences?
Discuss how Lucy can use inferential statistics to explore differences between
various populations of television audiences.
M
BApp
Chapter 10: Statistical Inferences for Two Populations 345
108.
Francis Allbritton is analyzing characteristics of Internet users, e.g., their
willingness to make an online purchase. Members of randomly selected "Web
Surfers" were asked whether they had made an online purchase. Their responses
are summarized in the following MINITAB report. (An affirmative response is a
success and is recorded as 1.)
Test and Confidence Interval for Two Proportions
Success = 1
Variable
Female
Male
X
27
40
N
150
150
Sample p
0.180000
0.266667
Estimate for p(Female) - p(Male): -0.0866667
90% CI for p(Female) - p(Male): (-0.165340, -0.00799341)
Test for p(Female) - p(Male) = 0 (vs not = 0): Z = -1.81
0.070
P-Value =
What sample sizes were used? Is there a staticstically significant difference in the
proportion of female Internet users who have made an online purchase and that of
male users?
M
BApp
346
Test Bank