1. Why is the range the most convenient measure of dispersion, yet the most imprecise measure of variability? When would you use the range?

2. Fill in the exclusive and inclusive ranges for the following items. Be sure to show your work below.

High Score Low Score Inclusive Range Exclusive Range

7 6

89 45

34 17

15 2

1 1

3. Why would you expect more variability on a measure of personality in college freshman than you would on a measure of height?

4. Why does the standard deviation get smaller as the individuals in a group score more similarly on a test?

5. For the following set of scores, compute the range, the unbiased and the biased standard deviations, and the variance. Use SPSS for this question but there may be some part of it you will have to do by hand.

31, 42, 35, 55, 54, 34, 25, 44, 35

6. The variance for a set of scores is 25. What is the standard deviation, and what is the range?

7. Use SPSS to find the range, the standard deviation, and the variance of each of the following sets of scores:

a. 3, 5, 7, 9

b. 0.2, 0.4, 0.6, 0.8

c. 3.5, 6.2, 9.3, 4.1, 5.5, 7.9