Answer Happy

vi What is the Var(@)? vii Suppose you are considering including an additional explanatory factor: age. How would you calculate the variance of the error term in the model that includes age and in the model that excludes age? viii Does excluding age have any effect on B3, the coefficient of sleep?
iv In a study on undergraduate student grades in econometrics, the students are asked how many hours they spend each week on five activities: studying, attending lectures, sleeping, working and leisure. Any activity is put into one of five categories, so that for each student, the sum of hours in the five activities must be 168. Does the following model satisfy the Gauss Markov assumptions of multiple linear regression? grade, = Bo+Bistudy+B lectures:+Bysleep + B work,+Byleisure;+ (2)