14.20 ● This exercise requires the use of a computer package.

The paper “Habitat Selection by Black Bears in an Intensively Logged Boreal Forrest” (Canadian Journal of Zoology [2008]: 1307–1316) gave the accompanying data on n 5 11 female black bears.

a. Fit a multiple regression model to describe the relationship between y 5 home-range size and the predictors x1 5 age and x2 5 weight.

b. Construct a normal probability plot of the 11 standardized residuals. Based on the plot, does it seem reasonable to regard the random deviation distribution as approximately normal? Explain.

(Hint: See Example 14.9.)

c. If appropriate, carry out a model utility test with a significance level of .05 to determine if the predictors age and weight are useful for predicting homerange size.