To begin the chi-square analysis, from the menus choose:

Analyze
Nonparametric Tests
Chi-Square...

Select Week of Response as the test variable.

The expected frequencies are the response percentages that the firm has historically obtained with bulk mail.

Select Values in the Expected Values group.

Type 6 as the first expected value, then click Add.

Repeat this process, consecutively adding the values 15.1, 18, 12, 11.5, 9.8, 7, 6.1, 5.5, 3.9, 2.1, and 2.

After the 12 values have been entered, click OK.