Chapter 1.3, Problem 105E

To determine

To calculate the interquartile range.

Answer to Problem 105E

Interquartile Range = 2.8

Explanation of Solution

Given:

Mean = 3.2

Standard deviation = 1.9

  

Calculation:

The first quartile is the median value of first 9 values, which means the 5^th value that divides the dataset of first 9 values in two equal parts.

Similarly, the third quartile will be the median value of last 9 values which means that it should divide the last 9 values in two equal parts.

  

Therefore, the First quartile = 1.9

And, Third quartile = 4.7

  $\begin{array}{l}{\text{Interquartile Range = Q}}_3-{\text{Q}}_1\\ \text{= 4}\text{.7 - 1}\text{.9}\\ \text{= 2}\text{.8 }\end{array}$