Consider a portion of simple linear regression results,

y = 105.40 + 39.17x1; SSE = 407,308; n = 30

In an attempt to improve the results, two explanatory variables are added. The relevant regression results are the following:

y = 4.87 + 19.47x1 - 26.31x2 + 7.31x3;

SSE = 344,784; n = 30

a. Formulate the hypotheses to determine whether x2 and x3 are jointly significant in explaining y.

b. Calculate the value of the test statistic.

c. At the 5% significance level, find the critical value(s).

d. What is the conclusion to the test?