Page 161 - Probability Demystified

150 CHAPTER 9 The Normal Distribution

ANSWERS

3 þ 6 þ 8 þ 2 þ 0 þ 5 þ 7 þ 8 þ 5 44
1. Mean ¼ ¼ ¼ 4:89
0 9
Median ¼ 5
Mode ¼ 5 and 8

332 þ 256 þ 300 þ 275 þ 216 þ 314 þ 192 1885
2. Mean ¼ ¼ ¼ 269:29
7 7
Median ¼ 275
Mode ¼ None

18 þ 6 þ 3 þ 9 þ 10 46
3. Mean ¼ ¼ ¼ 9:2
5 5
Median ¼ 9
Mode ¼ None

12 þ 8 þ 6 þ 1 þ 5 þ 4 þ 6 þ 2 þ 6 50
4. Mean ¼ ¼ ¼ 5:56
9 9

Median ¼ 6
Mode ¼ 6

7 þ 12 þ 11 þ 11 þ 5 þ 8 þ 11 þ 7 þ 8 þ 6 86
5. Mean ¼ ¼ ¼ 8:6
10 10

Median ¼ 8
Mode ¼ 11

Measures of Variability

In addition to measures of average, statisticians are interested in measures of
variation. One measure of variability is called the range. The range is the
difference between the largest data value and the smallest data value.
EXAMPLE: Find the range for 27, 32, 18, 16, 19, and 40.