\"A producer of various feed additives for cattle conducts astudy of the number of days of feedlot time required to bring beefcattle to market weight. Eighteen steers of essentially identi- calage and weight are purchased and brought to a feedlot. Each steeris fed a diet with a speciï¬c combination of protein content,antibiotic concentration, and percentage of feed supplement. Thedata are as follows:
STEER PROTEIN ANIBIO SUPPLEM TIME1 10 1 3 882 10 1 5 823 10 1 7 814 10 2 3 825 10 2 5 836 10 2 7 757 15 1 3 808 15 1 5 809 15 1 7 7510 15 2 3 7711 15 2 5 7612 15 2 7 7213 20 1 3 7914 20 1 5 7415 20 1 7 7516 20 2 3 7417 20 2 5 7018 20 2 7 69
8. Calculate the coefficient of determination and interpret.
9. Suppose x1 = PROTEIN, x2 = ANTIBIO and x3 = SUPPLEM, and youenter these predictors in the model in the order of x1, x2, x3.Find SSR(x2 | x1) and SSR(x3 | x1, x2). What do they mean?
10. Test whether adding ANTIBIO and SUPPLEM provides anyadditional predictive value, given that PROTEIN is already in themodel. Include all steps of a statistical test.
