The following data represents the number of hours students in a class study each week: 2, 3, 5, 7, 8, 12, 13, 14, 15, 15, 20. We want to create a frequency distribution table with 5 classes. What is the class width?

Step 1 ：Step 1: Identify the highest and lowest values in the data set. In this case, the highest value (H) is 20 and the lowest value (L) is 2.

Step 2 ：Step 2: Subtract the lowest value from the highest value to find the range of the data. \( R = H - L = 20 - 2 = 18 \)

Step 3 ：Step 3: Determine the number of classes. In this case, we have 5 classes.

Step 4 ：Step 4: Use the formula for class width, which is \( \text{Class Width} = \frac{R}{\text{number of classes}} \)

Step 5 ：Step 5: Substitute the values into the formula. \( \text{Class Width} = \frac{18}{5} = 3.6 \)