Chapter 7 Tables 307
there were 20 of them. As the size of the classes increases, the null hypothesis
increasingly overpredicts the number of courses that require calculus. For
example, if the null hypothesis were true, we would expect to see almost
10 courses with 201–500 students each require knowledge of calculus. The
observed number from the survey was 6. From this we conclude that class
size and a calculus prerequisite are not independent and that the courses that
require knowledge of calculus are more likely to be smaller.
Custom Sort Order
With ordinal data you want the values to appear in the proper order when
created by the PivotTable. If order is alphabetic or the variable itself is
numeric, this is not a problem. However, what if the variable being consid-
ered has a defi nite order, but this order is neither alphabetic nor numeric?
Consider the Interest variable from the Survey workbook, which measures
the degree of interest in a supplementary statistics text. The values of this
variable have a defi nite order (least, low, some, high, most), but this order
is not alphabetic or numeric. You could create a numeric variable based on
the values of Interest, such as 1 5 least, 2 5 low, 35 some, 4 5 high, and
55 most. Another approach is to create a custom sort order, which lets you
defi ne a sort order for a variable.
You can defi ne any number of custom sort orders. Excel already has some
built in for your use, such as months of the year (Jan, Feb, Mar, ... Dec), so if
your data set has a variable with month values, you can sort the data list by
months (you can also do this with PivotTables). Try creating a custom sort
order for the values of the Interest variable.
To create a custom sort order for the values of the Interest variable:
1 Click the Offi ce Button and then click Excel Options.
2 Click Popular from the list of Excel options.
3 Click the Edit Custom Lists button.
4 Click the List entries list box.
5 Type least and press Enter.
6 Type low and press Enter.
7 Type some and press Enter.
8 Type high and press Enter.
9 Type most and click Add.
Your Custom Lists dialog box should look like Figure 7-28.
