1. To compare the means of three samples -- perhaps three experimental treatments -- we should use this test:

• A. Pooled variance t-test assuming equal variance.
• B. Separate variance t-test assuming unequal variance.
• C. Z-test of difference of means.
• D. Analysis of variance

2. We are given a 2 rows by 3 columns contingency table want to know if the three proportions are different. We should use the (BLANK) test to compare the proportions in each column and the (BLANK) procedure to judge which pairs of proportions differ.

3. Assumptions of Regression: Plot residuals (Y) against independent variable(s) (X) to check for

• A. Linearity: To make sure that a straight line is the type of equation that fits best.
• B. Constant variability: To make that when you get confidence intervals to predict Y that they are accurate.
• C. Normality: To make sure that the confidence intervals and p-values that you get are accurate.
• D. Independence: To make sure that when you predict, future errors do not depend on past errors.

4. Assumptions of Regression: Plot residuals ( on Y axis) against the predicted values (Y-hat) (on X axis) to check for

A. Linearity: To make sure that a straight line is the type of equation that fits best.

• B. Constant variability: To make that when you get confidence intervals to predict Y that they are accurate.
• C. Normality: To make sure that the confidence intervals and p-values that you get are accurate.
• D. Independence: To make sure that when you predict, future errors do not depend on past errors.