Data Matters with Fathom! Dynamic Statistics™ software

Activity 8.2

Your task in this section is to redo the project from Section 8.1, replacing the equation for the observations.

In the last project, the equation was randomNormal(3,2). If you just wanted to try having the same mean, but different variances, you could edit the formula to use a different formula for each group.

In the formula window, select Functions, Conditional. Double-click on If. In the IF parentheses, type Group=A . Then click on the top question mark to enter the equation for Group A. You could use randomNormal(3,9). Click on the bottom question mark to enter the data for Group B. You could use randomNormal(3,99). That will give you draws from distributions with the same means but very different standard deviations.

To use such group-specific formulas for more than two groups, you will have to chain the IF statements: Click on the question mark, then select Functions, Conditional, If.

Can you beat my populations that led the ANOVA to reject the null hypothesis 49% of the time even though the means of both populations were the same?

Can you find distributions with equal means for which the ANOVA would reject the null hypothesis 50% of the time?