Consider a multiple regression analysis based on 50 data points and 5 explanatory variables. The number of degrees of freedom associated with the unexplained variation is Select one: O a. 55. O b. 50. O C. 49. O d. 45. O e. 44.In regression analysis, the F test statistic is based on the variation in response variable Y that is explained by the model and the variation in Y that is not explained by the model. The F test statistic is Select one: C) a. product of the explained and unexplained variations. O b. sum ofthe explained and unexplained variations. O 0. ratio of the explained variation to the unexplained variation. 0 d. ratio 0fthe unexplained variation to the explained variation. C) e. difference between the explained and unexplained variations. In regression analysis, every time an explanatory variable is added to the model it accounts for Select one: O a. more of the variability in the independent variables. O b. more of the variability in the response variable. O 0. less of the variability in the response variable. O d. less of the variability in the independent variables. O e. None of the above. In testing the overall utility of a linear regression model, our null hypothesis is that at least one of the regression slopes is not zero. Select one: O True O False