Math Word Problems Demystified - A Self Teaching Guide

2. 17, 18, 18, 25, 32 The middle value is 18; hence, the median is 18.


3. The value which occurs most often is 18, so the mode is 18.


4. The range is 32
   17 ¼15.


5. Follow these steps:

Find the mean. It is 22, as found in answer 1.

Subtract the mean from each data value:

32 
 22 ¼ 10

25 
 22 ¼ 3

18 
 22 ¼
 4

18 
 22 ¼
 4

17 
 22 ¼
 5

Square the differences:

102 ¼ 100

32 ¼ 9

ð
 4 Þ^2 ¼ 16

ð
 4 Þ^2 ¼ 16

ð
 5 Þ^2 ¼ 25

Find the sum of the differences:

100 þ 9 þ 16 þ 16 þ 25 ¼ 166

Divide the sum by 4:

166

4

¼ 41 : 5

Find the square root of 41.5:

ffiffiffiffiffiffiffiffiffi

41 : 5

p

¼ 6 : 44

282 LESSON 23 Word Problems in Statistics