Question

The Quick Change Oil Company has a number of outlets in the metropolitan Seattle area. The daily number of oil changes at the Oak Street outlet in the past 20 days are:
65 98 55 62 79 59 51 90 72 56
70 62 66 80 94 79 63 73 71 85

The data are to be organized into a frequency distribution.



Click here for the Excel Data File



How many classes would you recommend?





Organize the number of oil changes into a frequency distribution. (Round "Relative frequency" answers to 2 decimal places.)

Answer 1

Answer: 5 classes.

Step-by-step explanation:

You can use the  rule to determine the number of classes for a frequency distribution.

The  rule says that  where

is the number of classes

is the number of the data points

We know that the number of data points is  = 20.

Next, we start searching for  so that we can get a number 2 to the  that is larger that the number of data points.

This suggests that you should use 5 classes.