QUESTION 17 If the null hypothesis of no differences across groups is true, total variation should be equal to between-group variation. between-group variation should be equal to within-group variation. within-group variation should be equal to total variation. None of these are correct. All of these are correct. QUESTION 18 When comparing the independent samples t-test for means and the paired sample t-test for means, one is for univariate analysis while the other is for multivariate analysis. small sample sizes while the other is for large sample sizes. continuous variables while the other is for categorical variables. measures from separate groups while the other is for measures from the same group. All of these are correct. QUESTION 19 What should be done before trying to interpret individual regression coefficients? See whether there is an overall statistically significant relationship between the set of predictors and the outcome variable. Verify that the set of predictors can explain a meaningful portion of the variation in the outcome variable. Calculate the coefficient of multiple determination, or coefficient of determination, whichever is appropriate. All of these are correct. None of these are correct