I pledge that I will neither give nor receive any aid from any other person during this
exam, and that the work presented here is entirely my own.
Final Exam
Name: __________________________________________________
Score: __________ / 125
Please read each problem carefully and show all of your work.
1) Determine whether the number described is a statistic or a parameter.
a) A study of 6,076 adults in public
restrooms found that 23% did not wash
their hands before exiting.
__________________________________________________
b) A certain zoo found that 8% of its 843
animals were nocturnal.
__________________________________________________
2) Determine whether the data described are qualitative or quantitative.
a) State of residence.
__________________________________________________
b) Population of country of origin.
__________________________________________________
3) Determine whether the data described are nominal or ordinal.
a) The list of books that your friend read
for school for the past five months.
__________________________________________________
b) Responses to the question: How serious
is global warming? (Very serious,
somewhat serious, not too serious, not
serious, unsure)
__________________________________________________
4) Determine whether the data described are discrete or continuous.
a) Length (in minutes) of a rock song.
__________________________________________________
b) Number of cars owned.
__________________________________________________
5) Identify the kind of sample (systematic, cluster, stratified, or convenience) that is
described.
a) After a tornado, a disaster area is
divided into 150 equal grids. Fifty of the
grids are selected, and every occupied
household in the grid is interviewed to help
focus relief efforts on what residents
require the most.
__________________________________________________
b) Questioning students as they leave a
university parking lot, a researcher asks
385 students about their eating habits.
__________________________________________________
c) Every 25th person entering a library is
asked to choose his or her favorite author
from a list of five different authors that
includes a description of each.
__________________________________________________
d) Soybeans are planted of a 50-acre field.
The field is divided into one-acre subplots.
A sample is taken from each subplot to
estimate the harvest.
__________________________________________________
6) The data represents the lengths (in centimeters) of twenty Fijian Banded Iguanas.
Construct a frequency distribution using five classes.
52
63
53
63
53
64
54
65
54
67
55
69
55
70
56
74
60
74
62
75
7) The following data represent the income (in millions) of twenty highest paid athletes.
Construct a stem-and-leaf plot.
34
50
35
54
37
56
39
58
40
59
40
60
42
61
47
69
47
76
49
84
8) The cholesterol levels of a sample of six female employees are listed below. Find the
mean, median, and mode of the data.
203
125
225
154
235
125
9) The ages (in years) of a random sample of shoppers at a gaming store are shown.
Determine the range, variance, and standard deviation of the sample data set.
12
23
22
21
17
10) The table below displays the gender and favorite sport of a class of students. A student
is selected at random.
Basketball
Baseball
Tennis
Swimming
Total
Male
16
27
5
12
60
Female
2
6
16
16
40
Total
18
33
21
28
100
a) What is the probability that this student is male?
b) What is the probability that this student prefers basketball or baseball?
c) What is the probability that this student is female or prefers tennis?
d) Given that the person selected is male, what is the probability that he prefers basketball?
11) The probability that a person in the United States has type B+ blood is 8%. Four
unrelated people in the United States are selected at random. Find the probability that all
four have type B+ blood.
12) A factory received a shipment of 21 compressors, and the vendor who sold the items
knows there are 4 compressors in the shipment that are defective. Before the receiving
foreman accepts the delivery, he samples the shipment, and if too many compressors in the
sample are defective, he will refuse the shipment. If a sample of 3 compressors is selected,
find the probability that all in the sample are defective.
13) There are 16 finalists in a singing competition. The top four singers receive prizes. How
many ways can the singers finish first through fourth?
14) A tablet has 3 choices for an operating system, 5 choices for a screen size, 6 choices for
a processor, 9 choices for memory size, and 5 choices for a battery. How many ways can
you customize the tablet?
15) A class has 33 students. In how many different ways can four students from a group for
an activity?
16) In the following probability distribution, the random variable x represents the number
dogs per household in a small town. Compute the mean and standard deviation of the
random variable x.
𝒙
0
1
2
3
4
5
𝑷(𝒙)
0.63
0.22
0.09
0.03
0.02
0.01
17) Sixty (60%) of U.S. adults have very little confidence in newspapers. You randomly
select 10 U.S. adults. Find the probability that the number have very little confidence in
newspapers is
a) Exactly 5.
b) Less than 4.
18) In a recent year, the total scores for a certain standardized test were normally
distributed with a mean of 500 and a standard deviation of 10.5. Find the probability that a
randomly selected student who took the test had a score that was more than 524.
19) From a random sample of 40 months from January 2006 to December 2020, the mean
number of tornadoes per month in the United States was about 99. Assume the population
standard deviation is 109. Construct a 90% confidence interval for the population mean.
20) In a random sample of seven people, the mean driving distance to work was 22.1
minutes and the standard deviation was 5.5 miles. Assume the population standard
deviation is normally distributed and construct a 95% confidence interval for the
population mean.
21) The mean annual tuition and fees in the 2013 - 2014 academic year for a sample of 15
private colleges in California was $31,500 with a standard deviation of $7,250. A dotplot
shows that it is reasonable to assume that the population is approximately normal. Can you
conclude that the mean tuition and fees for private institutions in California is greater than
$35,000? Use the 𝛼 = 0.10 level of significance.
22) A business school professor computed a least-squares regression line for predicting the
salary in $1,000s for a graduate from the number of years of experience. The results are
presented in the following Excel output.
Intercept
Experience
Coefficients
54.7016023
2.38967954
a) Write the equation of the least-squares regression line.
b) Predict the salary for a graduate with 5 years of experience.