EXAM 3

1. Al and Joe are two county sheriff’s deputies assigned to watch for traffic violations. Their arrest and conviction records for May and June are shown below.

Who had the best conviction percentage in June?

A. Al

B. Joe

C. They are equal

D. Cannot tell by the data

2. The available following data set is the GPAs of the students in a statistics class.

1.93, 1.99, 2.00, 2.04, 2.12, 2.34, 2.55, 2.55, 2.75, 2.75,

2.80, 2.80, 2.85, 3.02, 3.12, 3.22, 3.31, 3.33, 3.45, 3.69

What percentile is a GPA of 2.34?

A. About the 6th

B. About the 15th

C. About the 30th

D. About the 60^{th}

3. Al and Joe are two county sheriff’s deputies assigned to watch for traffic violations. Their arrest and conviction records for May and June are shown below.

Who had the best conviction percentage overall?

A. Al

B. Joe

C. They are equal

D. Cannot tell by the data available

4. Find the mode(s) for the given sample data. 7.29, 7.41, 7.56, 7.29, 7.88, 7.99, 7.62

A. 7.56 B. 7.29 C. 7.577 D. 7.41

5. Find the standard deviation for the given data. Round your answer to one more decimal place than the original data. 22, 29, 21, 24, 27, 28, 25, 36

A. 4.8 B. 4.2 C. 2.8 D. 1.6

6. Find the standard deviation for the given data. Round your answer to one more decimal place than the original data.

15, 42, 53, 7, 9, 12, 14, 28, 47

A. 29.1 B. 16.6 C. 17.8 D. 15.8

7. Find the mode(s) for the given sample data. 20, 49, 46, 43, 49, 43, 49, 20, 22

A. 43 B. 49 C. 20 D. 22

8. The number of vehicles passing through a pharmacy drive-up line with two windows during each 15-minute period was recorded. The results are shown below. Find the median number of vehicles going through the line in a fifteen-minute period.

16 8 24 22 30 19 18 27 11 15

17 24 26 23 7 25 21 16 20 14

A. 19.3 B. 20.1 C. 19.5 D. 19.6

9. The mathematics SAT scores of the seven students in a mathematics seminar are 533, 553, 578, 586, 619, 626, and 633. Suppose that the student with the score 533 drops the seminar and is replaced by a student with a score of 765. What will happen to the mean and the median scores of the class?

A. The mean will increase; the median will be unchanged.

B. The median will increase; the mean will be unchanged.

C. Neither the mean nor the median will change.

D. Both the median and the mean will increase.

10. Use the range rule of thumb to approximate the standard deviation.

496,598, 503, 528, 565, 601, 576, 543

A. 170.2 B. 60.6 C. 26.25 D. 18.75

11. The federal government requires a car manufacturer to have a minimum miles per gallon (mpg) average over the models it makes. Suppose that the mpg’s for the five models of a manufacturer are 19, 21, 22, 28, and 18, and the government requirement is 27 mpg. The last of the models is to be redesigned to meet the government requirement. What must the new mpg of this model be to meet the requirement?

A. 27 mpg B. 29 mpg C. 30 mpg D. 54 mpg

12. The mathematics SAT scores of the seven students in a mathematics seminar are 533, 553, 578, 586, 619, 626, and 633. Suppose that the student with the score 533 drops the seminar and is replaced by a student with a score of 585. What will happen to the mean and the median scores of the class?

A. Neither the mean nor the median will change.

B. Both the median and the mean will increase.

C. The median will increase; the mean will be unchanged.

D. The mean will increase; the median will be unchanged.

13. Suppose that there are 400 students in your school class. What class rank is the 20th percentile?

A. 80 B. 40 C. 20 D. None of the above

14. The mathematics SAT scores of the seven students in a mathematics seminar are 538, 550, 570, 593, 610, 622, and 634. Suppose the student with the score 634 drops the seminar and is replaced by a student with a score of 600. What will happen to the mean and the median scores of the class?

A. Neither mean nor median will change.

B. The median will decrease, the mean will not change.

C. The median will not change, the mean will decrease.

D. Both mean and median will decrease

15. The normal monthly precipitation (in inches) for August is listed for 20 different U.S. cities. Find the median of the data.

A. 2.79 in. B. 3.45 in. C. 3.35 in. D. 2.45 in.

Data set was not included with this problem.

16. Consider the distribution of heights of all the players in the National Basketball Association. What would you expect the shape of the distribution to be?

A. Skewed right B. Skewed left C. Symmetric D. Multi-peaked

17. Find the mode(s) for the given sample data.

66, 25, 66, 13, 25, 29, 56, 66

A. 25 B. 56 C. 25 & 66 D. 66

18. Consider the distribution of mathematics SAT scores of students in honors calculus at a liberal arts college. What would you expect the shape and variation of the distribution to be?

A. Symmetric with little variationB. Symmetric with large variation

C. Skewed right with large variation D. Skewed left with little variation

19. Last year, a road construction firm hired 11 new employees. Their ages at hiring are listed below. Find the mean hiring age to one decimal place.

23 19 30 33 27 31 58 22 21 26 29

A. 29.1 B. 28.0 C. 29.2 D. 29.0

20. The federal government requires a car manufacturer to have a minimum miles per gallon (mpg) average over the models it makes. Suppose that the average mpg for the four models manufactured is 24 mpg and the government standard is 31 mpg. The manufacturer will add a model. What mileage must the new model get so that the manufacturer meets the government requirement?

A. 32 mpg B. 38 mpg C. 59 mpg D. None of the above

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