Use the p-values provided with the hypothesis tests to determine whether pairs of means are different.

·    If the p-value for a comparison is less than or equal to your chosen a-level, the difference between the means is significant.

·    If the p-value is greater than your chosen a-level, the difference between means is not significant.

Fisher's is less common than Tukey's because it does not control the simultaneous confidence level, which can decrease to an unacceptable level. Instead, Minitab calculates the simultaneous confidence level based on both the individual confidence level that you specify and the number of confidence intervals.

The individual confidence level is the percentage of times that a single confidence interval includes the true difference between factor levels if the study were repeated multiple times.

The simultaneous confidence level is the percentage of times that a group of confidence intervals all include the true differences between factor levels if the study were repeated multiple times.

Pairwise comparisons were conducted for the subject factor of the salary analysis. Because there are four levels of subject, this produces six pairwise comparisons. The hypothesis tests for the comparisons reveal the following:

·    The p-values for the differences between the mean for subject 1, and the means for subjects 2 (0.000), 3 (0.000), and 4 (0.000) are all lower than the chosen a-level of 0.05, which indicates that these differences are significant. Furthermore, the differences between the means (Difference of Means) are all positive, which indicates that teaching subjects 2, 3, and 4 each paid better than teaching subject 1.

·    The p-value for the difference between the means for subjects 2 and 3 (0.000) indicates that these means are significantly different as well. Furthermore, the difference (0.3067) is positive, which indicates that the mean for subject 3 is greater than that for subject 2.

·    The p-value for the difference between the means for subjects 2 and 4 (0.626) is greater than the chosen a-level, which indicates that these means are not significantly different.

·    The p-value for the difference between the means for subjects 3 and 4 (0.001) is lower than the chosen a-level, which indicates that the mean for subject 4 is significantly different from that of subject 3. Furthermore, the difference between the means (-0.2733) is negative, which indicates that teaching subject 3 paid better than teaching subject 4.