c. Let actsum be the sum of the math and English test scores, actsum = actmth + acteng. Using actsum in place of acteng gives gpa = 0.028 + 0.650 hsgpa + 0.0008 actmth +0.0122 actsum (0.168) (0.050) (0.0085) (0.0050) n = 754, R2 = 0.25 Can you reject Ho: Bactmth = Bacteng at any reasonable significance level? Explain. d. Dropping actmth and acteng from the original equation gives gpa = 0.03 + 0.683 hsgpa (0.190) (0.071) n = 754, R2 = 0.17 Are actmth and acteng jointly significant in the original equation at the 5% level? Justify your answer. e. Suppose that the gpa equation contains heteroskedasticity. What does this mean about the tests computed in parts b,c and d? c. Let actsum be the sum of the math and English test scores, actsum = actmth + acteng. Using actsum in place of acteng gives gpa = 0.028 + 0.650 hsgpa + 0.0008 actmth +0.0122 actsum (0.168) (0.050) (0.0085) (0.0050) n = 754, R2 = 0.25 Can you reject Ho: Bactmth = Bacteng at any reasonable significance level? Explain. d. Dropping actmth and acteng from the original equation gives gpa = 0.03 + 0.683 hsgpa (0.190) (0.071) n = 754, R2 = 0.17 Are actmth and acteng jointly significant in the original equation at the 5% level? Justify your answer. e. Suppose that the gpa equation contains heteroskedasticity. What does this mean about the tests computed in parts b,c and d