Suppose the following estimated equation. Standard errors are in parentheses. Y = 11 + 10.8X1 + 11.13X2 + 3.20X3 n = 25 R2 = 0.465 (7.5) (4.45) (4.88) (1.45) With a confidence interval estimation approach, you are to test if the variable of X, is negatively significant in the model. Use alpha = 0.05. Answer the followings. a. State the hypotheses. b. Construct the interval estimation. C. Is the variable of X1 negatively significant? Explain