Page 558 - Basic College Mathematics with Early Integers

SE CT I O N 7. 3 I MEAN, MEDIAN, AND MODE 535

13. Given the building heights, explain how you know, 14. Given the building heights, explain how you know,
without calculating, that the answer to Exercise 10 is without calculating, that the answer to Exercise 12 is
greater than the answer to Exercise 11. less than the answer to Exercise 9.

For Exercises 15 through 18, the grades are given for a student for a particular semester. Find the grade point average. If
necessary, round the grade point average to the nearest hundredth. See Example 2.

15. 16. 17. 18.
Grade Credit Hours Grade Credit Hours Grade Credit Hours Grade Credit Hours
B 3 D 1 A 3 B 2

C 3 F 1 A 3 B 2
A 4 C 4 A 4 C 3
C 4 B 5 B 3 A 3
C 1 B 3

For Exercises 19 through 27, find the mean, median, and mode, as requested. See Examples 1 and 3 through 6.

During an experiment, the following times (in seconds) were recorded:

7.8, 6.9, 7.5, 4.7, 6.9, 7.0
19. Find the mean. Round to the 20. Find the median. 21. Find the mode.
nearest tenth.

In a mathematics class, the following test scores were recorded for a student: 93, 85, 89, 79, 88, 91.
22. Find the mean. 23. Find the median. 24. Find the mode.

The following pulse rates were recorded for a group of 15 students:

78, 80, 66, 68, 71, 64, 82, 71, 70, 65, 70, 75, 77, 86, 72
25. Find the mean. 26. Find the median. 27. Find the mode.
28. How many pulse rates were higher than the mean? 29. How many pulse rates were lower than the mean?

Review

Write each fraction in simplest form. See Section 3.2.
12 6 4 18 35 55
30. 31. 32. 33. 34. 35.
20 18 36 30 100 75

Concept Extensions

Find the missing numbers in each set of numbers.

36. 16, 18, _________, _________, _________.The mode is 21.The median is 20.

37. _________, _________, _________, 40, _________.The mode is 35.The median is 37.The mean is 38.
38. Write a list of numbers for which you feel the median would be a better measure of central tendency than the mean.

39. Without making any computations, decide whether the median of the following list of numbers will be a whole
number. Explain your reasoning.
36, 77, 29, 58, 43