Straighterline Statistics Final Exam
Question 1: A bag contains marbles of different colors (red, yellow, and blue) and
different sizes (small and large). The probability of picking a blue marble out of the
bag is 0.10 and the probability of picking a large marble is 0.50. What is the
probability of picking a large blue marble?
A) 0.10
B) 0.05
C) 0.50
D) 0.60
Answer: B) 0.05
Question 2: A class of 25 students took a reading test before and after completing an
intensive vocabulary course to determine whether there was a change in scores in
either direction. The mean pretest score was 24, and the mean post test score was
32. The standard deviation of the difference was nine. What value of the T statistic
does this difference correspond to?
A) 3.5
B) 4.4
C) 5.2
D) 2.8
Answer: B) 4.4
Question 3: A coach wanted to determine whether her basketball team is performing
worse this year than in previous years. The coach knows that over the past several
years games, the team scored an average of 84 points. In the last year, with 36
games, they scored an average of only 71 points, with a standard deviation of 24
points. What T test statistic does this score correspond to?
A) -2.50
B) -3.25
,C) -4.00
D) -1.75
Answer: B) -3.25
Question 4: A dining guide reviewed all of the restaurants in a town. Only six
restaurants received a four star rating, 17 received three stars, 18 received two
stars, and nine received a one star rating. Based on this information, what is the
probability of a restaurant receiving a four star rating?
A) 0.06
B) 0.12
C) 0.18
D) 0.24
Answer: B) 0.12
Question 5: A guidance counselor wants to administer a survey to students in her
school. Why might she choose stratified sampling over simple random sampling?
A) To reduce the cost of the survey
B) To ensure that students from all grades are represented
C) To make data collection faster
D) To eliminate bias completely
Answer: B) To ensure that students from all grades are represented
Question 6: A high school student applies to both the Naval Academy and West
Point. The diagram shows his chances of being accepted to each school and the
chance that he will be accepted to both. What is the probability that he will be
accepted to at least one of the two schools?
A) 12%
B) 16%
, C) 20%
D) 24%
Answer: B) 16%
Question 7: A maple syrup manufacturer asked 100 customers to rate its brand of
maple syrup on a scale of one to 10. The mean rating was seven, with a sample
standard deviation of 1.5. Based on this sample, what is the 95% confidence interval
for the estimate of the population mean?
A) (6.5, 7.5)
B) (6.7, 7.3)
C) (6.0, 8.0)
D) (6.8, 7.2)
Answer: B) (6.7, 7.3)
Question 8: A regression analysis suggests that the number of children an employee
has predicts the number of personal days he/she will take off work. The slope of the
regression line is 3.2 and the lower bound of the confidence interval for this slope is
0.8. What is the upper bound?
A) 4.8
B) 5.6
C) 6.4
D) 4.0
Answer: B) 5.6
Question 9: A researcher asked children to complete a math test. Half of the children
are told they will be rewarded for every correct answer; the others will receive no
reward. The researcher will compare the mean test scores for the two groups. What
type of research design is this?
A) Survey
Question 1: A bag contains marbles of different colors (red, yellow, and blue) and
different sizes (small and large). The probability of picking a blue marble out of the
bag is 0.10 and the probability of picking a large marble is 0.50. What is the
probability of picking a large blue marble?
A) 0.10
B) 0.05
C) 0.50
D) 0.60
Answer: B) 0.05
Question 2: A class of 25 students took a reading test before and after completing an
intensive vocabulary course to determine whether there was a change in scores in
either direction. The mean pretest score was 24, and the mean post test score was
32. The standard deviation of the difference was nine. What value of the T statistic
does this difference correspond to?
A) 3.5
B) 4.4
C) 5.2
D) 2.8
Answer: B) 4.4
Question 3: A coach wanted to determine whether her basketball team is performing
worse this year than in previous years. The coach knows that over the past several
years games, the team scored an average of 84 points. In the last year, with 36
games, they scored an average of only 71 points, with a standard deviation of 24
points. What T test statistic does this score correspond to?
A) -2.50
B) -3.25
,C) -4.00
D) -1.75
Answer: B) -3.25
Question 4: A dining guide reviewed all of the restaurants in a town. Only six
restaurants received a four star rating, 17 received three stars, 18 received two
stars, and nine received a one star rating. Based on this information, what is the
probability of a restaurant receiving a four star rating?
A) 0.06
B) 0.12
C) 0.18
D) 0.24
Answer: B) 0.12
Question 5: A guidance counselor wants to administer a survey to students in her
school. Why might she choose stratified sampling over simple random sampling?
A) To reduce the cost of the survey
B) To ensure that students from all grades are represented
C) To make data collection faster
D) To eliminate bias completely
Answer: B) To ensure that students from all grades are represented
Question 6: A high school student applies to both the Naval Academy and West
Point. The diagram shows his chances of being accepted to each school and the
chance that he will be accepted to both. What is the probability that he will be
accepted to at least one of the two schools?
A) 12%
B) 16%
, C) 20%
D) 24%
Answer: B) 16%
Question 7: A maple syrup manufacturer asked 100 customers to rate its brand of
maple syrup on a scale of one to 10. The mean rating was seven, with a sample
standard deviation of 1.5. Based on this sample, what is the 95% confidence interval
for the estimate of the population mean?
A) (6.5, 7.5)
B) (6.7, 7.3)
C) (6.0, 8.0)
D) (6.8, 7.2)
Answer: B) (6.7, 7.3)
Question 8: A regression analysis suggests that the number of children an employee
has predicts the number of personal days he/she will take off work. The slope of the
regression line is 3.2 and the lower bound of the confidence interval for this slope is
0.8. What is the upper bound?
A) 4.8
B) 5.6
C) 6.4
D) 4.0
Answer: B) 5.6
Question 9: A researcher asked children to complete a math test. Half of the children
are told they will be rewarded for every correct answer; the others will receive no
reward. The researcher will compare the mean test scores for the two groups. What
type of research design is this?
A) Survey
