The following is the number of minutes to commute from home to work for a group of 25 automobile executives.

28, 25, 48, 37, 41, 19, 32, 26, 16, 23, 23, 29, 36, 31, 26, 21, 32, 25, 31, 43, 35, 42, 38, 33, 28

Organize the data into a frequency distribution.

So for my 2^k=25, I have k=5 for number of classes. Then to get the class interval, I take the highest value- lowest value and divide by 5. So I get (48-16)/5=6.6. So then wouldn't the class interval be 6.6? The correct answer is photographed below. I don't understand why the class interval changes throughout the frequency table and how to get that changed interval.