The data of Exercise 12.56 are also analyzed by a regression model using only protein co...

The data of Exercise 12.56 are also analyzed by a regression model using only protein content as an independent variable, with the following output:

a. Write the regression equation.

b. Find the value.

c. Test the null hypothesis that the coefficients of ANTIBIO and SUPPLEM are zero at α = .05.

REFERENCE:

12.56 : A producer of various feed additives for cattle conducts a study of the number of days of feedlot time required to bring beef cattle to market weight. Eighteen steers of essentially identical age and weight are purchased and brought to a feedlot. Each steer is fed a diet with a specific combination of protein content, antibiotic concentration, and percentage of feed supplement. The data are as follows:

Computer output from a Systat regression analysis follows:

a. Write the regression equation.

b. Find the standard deviation.

c. Find the value.

d. How much of a collinearity problem is there with these data?