Question

A recent survey determined the IQ score of a random selection of residents of Alaska. The accompanying relative frequency distribution table summarized the results.

Identify the class width for the given relative frequency distribution.

Answer 1

The class width is 20

Explanation:

In a frequency or a relative frequency distribution the class width is calculated as the difference between the lower or upper class limits of consecutive classes. A point to note is that all the categories or classes usually have the same class width.

We use the first two classes to calculate the class width by using their respective upper limits;

Class width = 89 - 69

Class width = 20