DATA: 199.0 16.0
205.0 16.0
196.0 16.0
200.0 16.0
218.0 24.0
220.0 24.0
215.0 24.0
223.0 24.0
237.0 32.0
234.0 32.0
235.0 32.0
230.0 32.0
250.0 40.0
248.0 40.0
253.0 40.0
246.0 40.0

Required:
a. Perform the F test to determine whether or not is lack of fit of a linear regression function; use a .01. State the alternatives, decision rule, and conclusion.
b. Is there any advantage of having an equal number of replications at each of the X levels?
c. Does the test in part (a) indicate what regression function is appropriate when it leads to the conclusion that the regression function is not linear? How would you proceed?