Suppose X, is a numerical variable and X2 is a dummy variable with two categories and the regression equation for a sample of n = 24 is Y, = 4+6X,, + 5X2;- a. Interpret the regression coefficient associated with variable X1- b. Interpret the regression coefficient associated with variable X2. c. Suppose that the tSTAT test statistic for testing the contribution of variable X2 is 3.23. At the 0.01 level of significance, is there evidence that variable X2 makes a significant contribution to the model? a. Interpret the regression coefficient associated with variable X,- Holding constant the effect of | |for each increase of one unit in the predicted mean value of Y by a positive change of |unit(s). b. Interpret the regression coefficient associated with variable X2. Holding constant the value of | changing the value of |V from to is estimated to the predicted mean value of Y by a positive change of ] unit(s). c. Determine the null and alternative hypotheses. Ho State the test statistic. ISTAT =(Round to two decimal places as needed.) Find the p-value. p-value = (Round to three decimal places as needed.) State the conclusion. Choose the correct answer below. O A. Do not reject Ho. There is insufficient evidence at the 0.01 level of significance that variable X2 makes a O B. Do not reject Ho. There is sufficient evidence at the 0.01 level of significance that variable X2 makes a significant significant contribution to the model. contribution to the model. O C. Reject Ho. There is sufficient evidence at the 0.01 level of significance that variable X2 makes a significant O D. Reject Ho. There is insufficient evidence at the 0.01 level of significance that variable X2 makes a significant contribution to the model. contribution to the model