Chapter 2.1, Problem 37E

To determine

Interquartile range for the distribution of absences.

Answer to Problem 37E

Interquartile range,

  $IQR=3$

Explanation of Solution

Given information:

  

Interquartile range is the difference between the 1^st and 3^rd quartile.

The property of 1^st quartile reveals that 25% of the data values are below it.

The property of 3^rd quartile reveals that 75% of the data values are below it.

From the graph, we can see that

1^st quartile (or 25%) is at 2 absences.

Such that

  $Q_1=2$

And

3^rd quartile (or 75%) is at 5 absences.

Such that

  $Q_2=5$

The difference between the 1^st and 3^rd quartile gives the interquartile range.

Thus,

  $IQR=Q_3-Q_1=5-2=3$