EXAMPLE 9.4

Software output for vaccinations and political party. Figure 9.1 shows the output from JMP, Minitab, and SPSS for the vaccination data of Example 9.3. For now, we will just concentrate on the different distributions. Later, we will explore other parts of the output.

The three packages use similar displays for the distributions. In the cells of the table, we find the counts, the conditional distributions of the column variable for each value of the row variable, the conditional distributions of the row variable for each value of the column variable, and the joint distribution. All of these are expressed as percents rather than proportions.

528

Let’s look at the entries in the upper-left cell of the JMP output. We see that there are 230 Democrats who think vaccinations should not be required. These 230 represent 13.56% of the study participants. They represent 23.98% of the Democrats in the study. And they represent 47.13% of the respondents who think vaccinations should not be required. The marginal distributions are in the rightmost column and the bottom row. Minitab and SPSS give the same information but not necessarily in the same order.