in an experiment, a researcher compares three different drugs (say, A, B, and C) used to reduce high blood pressure. for each drug, 15 patients received the drug. The response variable is systolic blood pressure (Y). in addition to the type of drug, a quantitative predictor, dose (X) will be used in a regression model for predicting Y. Let Z1=1 if drug is A, 0 otherwise, Z2=1 if drug is B, 0 otherwise, and Z3=1 if drug is C, 0 otherwise. let SSE_F and SSE_R be the error sums of squares for the full and reduced models and MSE_F and MSE_R be the mean square errors for the full and reduced models. What is the test statistic to test the null hypothesis is