# Week 2 Assignment: Frequency Tables

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William wishes to view a frequency table for grouped data using his monthly credit card statements for the last 20 months, shown below. Construct the table for William using six classes.

1312, 1303, 809, 1477, 1263, 1444, 894, 1051, 1485, 1433, 1132, 1221, 1179, 945, 995, 1179, 1172, 1373,  906, 955 Note that the data is not ordered and that we have been asked to use 6 classes.

To determine the class width, use the formula:

Max Value−Min ValueNumber of Classes=1485−8096≈112.7

Since the data values are integers, round up to the next integer, 113. The minimum value, 809, is the lower class limit of the first class. To find all other lower class limits, add the class width, 113. For example, the second lower class limit would be: 809+113=922.

The upper class limit for each row is one less than the lower class limit from the following row. For example, the upper class limit for the first row is 922−1=921. You can also add the class width to one upper class limit to get the upper class limit for the next row.

To find the frequency for each class, count the number of data values that fall within the range of each class. For example, the data values 809, 894, and 906 fall within the range of the first class, 809-921. So, the frequency of this class is 3.