Final answer:
The class width in a frequency distribution is the bin size and is calculated by dividing the range of the data by the number of classes. For instance, with a range from 32.5 to 100.5 and five intervals, the class width is 13.6. Consistency in assigning data to intervals is essential for histograms.
Step-by-step explanation:
The class width for a frequency distribution is the difference between the upper and lower boundaries of any class (interval). It is essentially the bin size and determines how the data is grouped into intervals within a histogram. Calculating the class width involves deciding on the number of classes you want to use, which typically ranges from five to fifteen for clarity. Once you've determined the number of classes, the class width can be found by dividing the range of the data by the number of classes.
For example, if we take the range of data from 32.5 to 100.5 and we want five intervals, we would subtract the smallest value (32.5) from the largest value (100.5) to get the range, and then divide that range by the number of intervals (5). The calculation would be (100.5 - 32.5) ÷ 5, which equals 13.6. Therefore, the class width would be 13.6.
Keep in mind, when setting up histograms, consistency is key in deciding which data values fall into which interval. Some researchers count the data values that fall on the right boundary as part of the class interval, while others do not, except for the first interval where both boundaries typically include the data values.