Answer:
Width of intervals: 8
Step-by-step explanation:
We first look at how data is represented in a stem-leaf diagram.
Any number of the left (before -) is the stem and all numbers on right (after -) are the leaves. Each combination of stem and leaf represents one number. For example: 1 - 332 represents: 13, 13, 12.
Our data is as follows:
13, 13, 12, 24, 25, 31, 31, 35, 37, 42, 43, 41, 52, 51, 51, 52
To calculate the width of the frequency distribution chart, we have the following formula:
![Class\ width = \frac{Range}{Number\ of\ classes}](https://tex.z-dn.net/?f=Class%5C%20width%20%3D%20%5Cfrac%7BRange%7D%7BNumber%5C%20of%5C%20classes%7D)
The range of any data set = Maximum value in the data set - Minimum value in the data set
Maximum value in this case as seen from the data is 52 and minimum is 12.
Range = 52 - 12 = 40
Since we had only 5 stems in the data, we shall use that as the number of classes required in the frequency distribution chart.
![Class\ width = \frac{40}{5} = 8](https://tex.z-dn.net/?f=Class%5C%20width%20%3D%20%5Cfrac%7B40%7D%7B5%7D%20%20%3D%208)
Hence, the class width in this data set will be 8.
To make the intervals, we begin from the minimum value and add 8 to it. The intervals will be:
12 - 20
20 - 28
28 - 36
36 - 44
44 - 52
Observe, that all the values of the stem lie within each interval.
For example, there are 3 values for stem 1: 12, 13, 13 and each lie in the first interval 12 - 20.
Next, the values of stem 2 are 24 and 25. Each of these value lie in the second interval 20 - 28; and henceforth.