Chapter 5 sample online exam questions:
1. Question: A relative frequency distribution shows:
Student Answer:
1. the number of scores of each kind
2. the number of scores at or below each possible score
3. the proportion of scores of each kind
4. The proportion of scores at or below each possible score
2. Question: What is the minimum size of a random sample that will allow you to make a
point estimate of mu?
Student Answer:
1. 10% of the population
2. 1% of the population
3. .1% of the population
4. 1 score
5. None of the above (1, 2, 3, or 4) is correct
3. Question: Assume you have five samples. Each sample has 10 participants. The
samples come from the same population. To find your best estimate of sigma2, you
divide SSW by:
Student Answer:
1. 9
2. 45
3. 49
4. 50
5. You don’t divide, you multiply
6. None of the above is correct
4. Question: Assume you have three samples each with 10 participants. The samples
come from the same population. To find your best estimate of sigma2, you:
Student Answer:
1. Square sigma
2. Divide the sum of squares around the overall mean by three
3. Divide the sum of squares around the overall mean by twenty-seven
4. Only 1 and 2
5. Only 2 and 3
6. None of the above (1, 2, or 3) is correct
5. Question: The best point estimate of the squared effects of individual differences and
measurement problems is/are:
Student Answer:
1. Sigma2
2. MSW
3. dfW
4. Only 1 and 2
5. Only 2 and 3
6. None of the above (1, 2 and 3) is the best point estimate of sigma2
6. Question: A drug company took four random samples with three people in each sample
of cholesterol reduction after taking their new drug, ArtFree, for a month. In the first
sample, Al’s cholesterol went down 15 points, Barbara’s went down 13 points, Chuck's
went down 14 points. In sample two, Donna's cholesterol went down 16 points, Ed’s
cholesterol went down 18 points, Francine's went down 14 points. In sample three,
George's cholesterol went down 25 points, Harriet's went down 19 points, and Ira's went
down 16 points. In the final sample, Jenny's cholesterol went down 11 points, Karl's went
down 8 points, and Linda’s 14 points. Which of the answers below is the best estimate of
sigma2?
Student Answer:
1. 17.50
2. 8.75
3. 5.83
4. 6.36
5. None of the above are correct
7. Question: Jane does a study with 5 samples randomly chosen from a population. There
were 10 participants in the first sample and 18 participants in the second sample.
Similarly, there were 27 participants in the third sample, 21 in the fourth sample, and 36
in the fifth sample. Compute dfW.
Student Answer:
1. 112
2. 107
3. 111
4. 5
5. None of the above are correct
8. Question: Jane does a study with 3 samples randomly chosen from a population. There
were 14 participants in the first sample and the sum of squared deviations around its
group mean was 56.00. There were 9 participants in the second sample and the sum of
squared deviations around its group mean was 51.00. Similarly, there were 12
participants in the third sample and the sum of squared deviations around its group mean
was 53.00. Estimate the average squared distance of scores in the population from mu.
Student Answer:
1. 4.57
2. 5.00
3. 5.38
4. 4.85
5. None of the above are correct
9. Question: An investigator does a study with 6 people in each of 5 groups. The total
sum of squares within group is 625 (SSW = 625.00). What is your best estimate of
sigma?
Student Answer:
1. 4.56
2. 8.75
3. 5.00
4. 11.18
5. None of the above are correct
Answers-CH5: 1. the proportion of scores of each kind. 2. 1 score. 3. 45. 4. None of
the above (1, 2, or 3) is correct. 5. MSW. 6. 8.75. 7. 107.
8. 5.00. 9. 5.00.
Chapter 6 sample online exam questions:
1. Question: How do you convert individual t scores to raw scores?
Student Answer:
1. You take the estimated standard error for samples the same size as yours,
multiply it by t and add the result to the mean of your random sample
2. You take the estimated standard deviation, multiply it by t and add the result to
the mean of your random sample
3. Use the formula: X= X-Bar + ts
4. Only 1 and 2 are correct
5. Only 2 and 3 are correct
6. None of the above (1, 2, or 3) is correct
2. Question: Which of the following are correct statements about the estimated standard
error of the mean (sX-Bar)?
Student Answer:
1. The estimated average unsquared difference of sample means from each other
is called the standard error of the mean
2. sX-Bar decreases as the size of the sample increases
3. sX-Bar is the best estimate of the average unsquared distance of sample means
from mu
4. Both 1 and 2, but not 3 are correct
5. Both 2 and 3, but not 1 are correct
6. All of the above (1, 2 and 3) are correct
3. Question: Which of the following is/are true about t scores?
Student Answer:
1. You compute t scores when you must estimate mu and sigma
2. t scores are estimated Z scores
3. To compute t scores, you must estimate mu and sigma from a random sample
4. Only 1 and 2 are true
5. Only 2 and 3 are true
6. All of the above (1, 2 and 3) are true
4. Question: According to your book and class discussion, which of the following
samples is/are random and therefore representative of the population from which it is
drawn
Student Answer:
1. People counted by the U.S. Census Bureau in during the 2000 census.
(Population = U.S. residents.)
2. Voters in a Presidential election. (Population = registered voters.)
3. One student in a 1000 person Intro Psych class selected by having a random
number drawn from a box containing one number for each student. (Population =
Students in the class.)
4. Both 1 and 2 are random samples, 3 is not
5. Both 1 and 3 are random samples, 2 is not
6. one of the above (1, 2, or 3) is a random sample
5. Question: You have a random sample (n=10) with a sample mean of 15.00 and an
estimated standard deviation of 4.00. Jack, who was not in your original sample, scores
20. How do you find his t score?
Student Answer:
1. You add his score to your random sample, recompute X-Bar and s, and then
compute Jack’s t score using the t formula for individual scores
2. You add his score to your random sample, recompute X-Bar but use the
estimate of sigma you obtained from your original random sample, and then compute
Jack’s t score using the t formula for individual scores
3. Subtract 15.00 from 20.00 and divide the result by 4.00
4. Only 1 and 3 are correct
5. Only 2 and 3 are correct
6. None of the above (1, 2, or 3) is correct
6. Question: A drug company took a random sample of 6 schizophrenic patients to see if
the drug would decrease symptoms of schizophrenia. Ability to function normally was
measured on a scale that went from 0-100 with 0 indicating no ability to care for oneself
and 100 representing completely normal functioning. Participants were measured on this
index after taking their new drug, ThinkRight, for a month. Al’s functioning went up 21
points, Barbara’s went up 18 points and Chuck’s went up 15 points. Donna’s functioning
went up22 points, Ed’s went up 15 points and Francine went up 17 points. The results
were then translated into t scores. Which of the answers below is the best estimate of
Donna’s t score?
Student Answer:
1. +1.00
2. +1.35
3. -0.27
4. -0.34
5. None of the above are correct
7. Question: Jenny studies a sample (n = 14) randomly drawn from a population who all
took a course in increasing self-esteem. She wanted to see if after the course, students
really made a number of new friends as the course had advertised. Six months after the
end of the course, the number of new friends among the 14 participants ranged from 0 to
17 with a mean of 10.00. The sum of the squared deviations around the sample mean
(SSw) equaled 52.00. Jenny then transformed her findings to t scores. Tom’s transformed
score was t=2.00. How many new friends had he made?
Student Answer:
1. 14.00
2. 18.62
3. 15.00
4. 13.85
5. None of the above are correct
8. Question: In a group with 13 people, John has a t score of 3.055. What is his percentile
rank?
Student Answer:
1. 3
2. 99.5
3. 5
4. It is impossible to know given the t table in the book
5. None of the above (1, 2, 3, or 4) are correct
9. Question: A researcher uses a sample of 20 people to find that s = 24.00. What would
you estimate the standard error of the mean to be for samples of size 16 (n = 16)?
Student Answer:
1. 6.00
2. 3.00
3. 4.00
4. It is impossible to know
5. None of the above are correct
10. Question: You obtain a random sample comprising 25 research participants (n = 25)
from the population. You compute MSw = 225.00 and its square root, the estimated
standard deviation, equals 15.00 (s = 15.00). The sample mean = 25.00. Compute the
CI.99 for mu.
Student Answer:
1. 19.74 < mu < 33.39
2. 18.81 < mu < 79.74
3. 18.81 < mu < 31.19
4. 16.61 < mu < 33.39
5. None of the above are correct
Answers-CH6: 1. Only 2 and 3 are correct. 2. Both 2 and 3, but not 1 are correct. 3. All
of the above (1, 2 and 3) are true. 4. One student in a 1000 person Intro Psych class
selected by having a random number drawn from a box containing one number for each
student. (Population = Students in the class). 5. Subtract 15.00 from 20.00 and divide the
result by 4.00. 6. +1.35. 7. 14.00.
8. 99.5. 9. 6.00.
10. 16.61 < mu <
33.39.
Chapter 7 sample online exam questions:
1. Question: There is a relationship between two variables such that high scores on the
first variable are a bit more likely to go with low scores on the second variable than they
are with high scores. Alternatively, low scores on the first are a bit more likely to go with
high scores on the second variable, than with low scores. This correlation is called
Student Answer:
1. Strong and Positive
2. Weak and Positive
3. Strong and Negative
4. Weak and Negative
5. None of the above
2. Question: There is a relationship between two variables such that as the values on one
variable gradually increase, values of the other variable generally tend to decrease. This
kind of correlation is called
Student Answer:
1. Positive
2. Negative
3. Weak
4. Strong
5. None of the above
3. Question: The estimated average squared difference between the ZX and ZY scores
Student Answer:
1. Is only peripherally related to Pearson’s r
2. Is based on the differences between the tX and tY scores in the sample
3. Both 1 and 2 are true
4. Neither 1 nor 2 is true
4. Question: If you compute r and rho from the same raw data, numerically
Student Answer:
1. They will be identical
2. They will be close to each other
3. They will be far from each other
4. It is impossible to tell how they will be related
5. Question: A true graph
Student Answer:
1. Must display frequencies
2. Must show the whole population
3. Must show scores on two or more variables with each data point
4. All of the above (1, 2, and 3) are true
5. None of the above (1, 2, or 3) is true
6. Question: A researcher studied reaction time to two tasks with 4 randomly selected
undergraduates: Al, Barbara, Chuck, and Donna. Al’s reaction time on task 1 was 500
milliseconds, while on task 2 it was 650. Barbara’s reaction time on task 1 was 650
milliseconds, while on task 2 it was 658. Chuck’s reaction time on task 1 was 500
milliseconds, while on task 2 it was 664. Donna’s reaction time on task 1 was 490
milliseconds, while on task 2 it was 672. Let reaction time on task 1 be the X variable and
task 2 the Y variable. Estimate the average squared difference between the ZX and ZY
scores in the population from the tX and tY scores in the sample.
Student Answer:
1. Estimated average squared distance = 2.14
2. Estimated average squared distance = 2.96
3. Estimated average squared distance = 1.21
4. Estimated average squared distance = 1.54
5. None of the above are true
7. Question: A researcher studied the relationship of self-esteem at age 13 (as measured
by a scale that went from 1-20 (with higher numbers equaling greater self-esteem) and
life satisfaction at age 35 on a scale from 0-100 with higher numbers equaling greater
satisfaction. Because men and women may differ on both the meaning of self-esteem and
the factors underlying life satisfaction only women were included in the first study. Let
self-esteem be the X variable and life satisfaction the Y variable. Edie scored 20 on X
and 36 on Y, Francine scored 19 on X and 33 on Y, Ginny scored 15 on X and 30 on Y,
Heather scored 14 on X and 26 on Y, Ivy scored 10 on X and 23 on Y, Jenny scored 9 on
X and 19 on Y, Kathy scored 4 on X and 15 on Y. Therefore the mean of the X variable
was 13.00 and the sum of squares for X was 196.00. Similarly the mean of the Y variable
was 26.00 and the sum of squares for Y was 344.00. Compute the tX and tY scores and
then compute r, Pearson’s correlation sample.
Student Answer:
1. r = 0.99
2. r = 0.72
3. r = 0.69
4. r = 0.79
5. None of the above are true
8. Question: A researcher studied the relationship of self-esteem at age 13 (as measured
by a scale that went from 1-20 (with higher numbers equaling greater self-esteem) and
life satisfaction at age 35 on a scale from 0-100 with higher numbers equaling greater
satisfaction. Because men and women may differ on both the meaning of self-esteem and
the factors underlying life satisfaction, only women were included in the first study. Of
the original random sample of 10,000 women, whose self-esteem had been measured
when they were 13, 42 were randomly chosen for the life satisfaction sample. Self-esteem
was designated the X variable and life satisfaction the Y variable. The sum of the squared
differences between the tX and tY scores was 12.30. Compute your best estimate of rho.
Student Answer:
1. Best estimate of rho = 0.65
2. Best estimate of rho = 0.75
3. Best estimate of rho = 0.85
4. Best estimate of rho = 0.95
5. None of the above are true
Answers-CH7: 1. Use the critical values for 40 df. 2. Negative. 3. Is based on the
differences between the tX and tY scores in the sample. 4. They will be identical. 5.
Must show scores on two or more variables with each data point. 6. None of the above
are true. 7. r = 0.99. 8. Best estimate of rho = 0.85.
Chapter 8 sample online exam questions:
1. Question: The r table shows critical values for 40 and 50 degrees of freedom. You have
n=51 in your sample. What can you do?
Student Answer:
1. Use the critical values for 40 df
2. Use the critical values for 50 df
3. It is appropriate to use either the critical value for 40 or 50 df
4. You can’t do any of the above (1, 2, nor 3)
2. Question: The reason you can not use the regression equation when predicting from a
significant correlation and a score on X that is outside the range of X scores seen in your
random sample is:
Student Answer:
1. Because the equation is only valid in limited cases
2. That the correlation may not stay linear outside the range you originally saw
3. Both 1 and 2
4. Neither 1 nor 2
3. Question: To make a prediction of a Y score based on r and tX, you must
Student Answer:
1. Compute the sample mean and estimated standard deviation of Y
2. Have a statistically significant correlation
3. Have X be in the appropriate range of scores
4. Only 1 and 2 are necessary
5. All of the above (1, 2, and 3) are necessary
4. Question: If you use the equation tY’=rtX, the average estimated unsquared error for
predicted scores on the Y variable:
Student Answer:
1. Is your estimated average unsquared vertical distance between the regression line
and actual scores on the Y variable
2. Is called the estimated standard error of the estimate
3. Is the same as the estimated standard error of the mean
4. Only 1 and 2 are true
5. Only 2 and 3 are true
6. All of the above (1, 2, and 3) are true
5. Question: The estimated standard error of the estimate
Student Answer:
1. Is your estimated average unsquared error when you use the regression equation
2. Is the square root of the residual mean square
3. Can only be computed when r is significant
4. None of the above (1, 2, or 3) is true
5. All of the above (1, 2, and 3) are true
6. Question: A researcher studied the relationship of self-esteem at age 13 (as measured
by a scale that went from 1-50 (with higher numbers equaling greater self-esteem) and
life satisfaction at age 35 on a scale from 0-100 with higher numbers equaling greater
satisfaction. Because men and women may differ on both the meaning of self-esteem and
the factors underlying life satisfaction, only women were included in the first study. Let
self-esteem be the X variable and life satisfaction the Y variable. Edie scored 7 on X and
25 on Y, Francine scored 9 on X and 30 on Y, Ginny scored 11 on X and 40 on Y,
Heather scored 13 on X and 35 on Y, Ivy scored 15 on X and 50 on Y, Jenny scored 17
on X and 55 on Y, Kathy scored 19 on X and 45 on Y, Linda scored 13 on X and 40 on
Y. Therefore, the mean of the X variable was 13.00 and the sum of squares for X was
112.00. Similarly, the mean of the Y variable was 40.00 and the sum of squares for Y
was 700.00. Samantha, who was not part of the sample but was a member of the
population from which the sample was drawn, scored 10 on the self-esteem measure.
Estimate Samantha’s score on life satisfaction at age 35.
Student Answer:
1. Y' = 27.14
2. Y' = 33.57
3. Y' = 40.00
4. Y' = 46.43
5. None of the above are correct
7. Question: A researcher studied the relationship of number of evenings spent with
friends in the last month and reported disappointment with college life among male
college undergraduates. 51 participants were randomly chosen at a large Midwestern
university and filled out a questionnaire about college that included a question about
overall disappointment. Disappointment ratings (the X variable) ranged from 2 to 15 on a
20 point scale in which higher scores represented greater disappointment. The mean
disappointment was 12.00 with an estimated standard deviation of 3.00. Number of
evenings with friends, the Y variable, ranged from 0.00 to 20.00 with a mean of 8.00 and
an estimated standard deviation of 1.50. The sum of the squared differences between the
tX and tY scores was 175.00. John, a male undergraduate at this university who was not
part of the original sample, had a disappointment score of 14. What is your best estimate
of how many evenings he spent with friends?
Student Answer:
1. Y' = 12.08
2. Y' = 13.08
3. Y' = 7.25
4. Y' = 15.92
5. None of the above is correct
8. Question: A researcher studied the relationship of carbohydrate craving to weight
change during freshman year at college. She found a linear correlation of + 0.700
between degree of craving reported on a questionnaire and weight gain among the 24
participants in this study. Participants were randomly chosen from the freshman class at a
large East Coast college. The sum of squared deviations around the mean of the Y
variable for the participants in the study was 660.00. If r is significant, compute the
standard error of the estimate (sEST) for the Y variable.
Student Answer:
1. sEST = 4.52
2. sEST = 3.91
3. sEST = 5.65
4. sEST = 6.22
5. None of the above are correct
Answers-CH8: 1. Weak and Negative. 2. That the correlation may not stay linear outside
the range you originally saw. 3. All of the above (1, 2, and 3) are necessary. 4. Only 1
and 2 are true. 5. All of the above (1, 2, and 3) are true. 6. Y' = 33.57. 7. Y' = 7.25.
8. sEST = 3.91.