Please choose the answer that you think is appropriate 1.1 To test whether or not the population regression function is linear rather than a polynomial of order r, a. check whether the regression for the polynomial regression is higher than that of the linear regression. b. compare the TSS from both regressions. c. look at the pattern of the coefficients: if they change from positive to d. use the test of (r-1) restrictions using the F-statistic. 1.2 In the case of regression with interactions, the coefficient of a binary a. there are really problems in interpreting these, since the l b. for the case of interacted regressors, the binary variable coefficient repre- negative to positive, etc., then the polynomial regression should be used variable should be interpreted as follows: defined. scuts the various intcropts for the case when the binary varriable cquals one. c. first set all explanatory variables to one, with the exception of the binary variables. Then allow for each of the binary variables to take on the value of one sequentially. The resulting predicted value indicates the effect of the binary variable. d. first compute the expected values of Y for each possible case described by the set of binary variables. Next compare these expected values. Each coefficient can then be expressed either as an expected value or as the difference between two or more expected valucs.