Why is it generally recommended that the number of classes in a frequency distribution be between $5$ and $20$?

• A. Because having fewer than $5$ classes always results in a perfectly normal distribution.
• B. Because too few classes can oversimplify the data, while too many classes can make patterns difficult to detect.
• C. Because the number of classes must always equal the number of data points.
• D. Because using more than $20$ classes guarantees that all class intervals will have the same frequency.

Answer: (B)

Verified step by step guidance

1. Understand that the number of classes in a frequency distribution affects how well the data's pattern is represented.
2. Recognize that having fewer than 5 classes can oversimplify the data, causing important details and variations to be lost.
3. Know that having more than 20 classes can make the distribution too detailed, which may obscure overall patterns and make interpretation difficult.
4. Realize that the goal is to balance detail and clarity, so choosing between 5 and 20 classes helps to reveal meaningful trends without overwhelming or oversimplifying the data.
5. Remember that the number of classes does not have to equal the number of data points, nor does it guarantee equal frequencies in each class.