7.8 Joint Hypothesis Testing -Testing the Joint Hypothesis That B, =B2=0 or R2=0 I. Null hypothesis H⌒:B,=B2=0 (745) H:R2=0 (746) Which means that the two explanatory variables together have no influence on Y, means the two explanatory variables explain zero percent of the variation in the dependent variable (1)Why this test? practice, in a multiple regression one or more variables individually have no effect on the dependent variable but collectively they have a significant impact on it7.8 Joint Hypothesis Testing －－Testing the Joint Hypothesis That B2=B3 =0 or R2=0 1.Null hypothesis: H0 :B2=B3 =0 (7.45) H0 :R2=0 (7.46) Which means that the two explanatory variables together have no influence on Y, means the two explanatory variables explain zero percent of the variation in the dependent variable. (1)Why this test? In practice, in a multiple regression one or more variables individually have no effect on the dependent variable but collectively they have a significant impact on it