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.

Age

(years)

Weight

(kg)

Home-Range Size (km2

) 10.5 54 43.1 6.5 40 46.6 28.5 62 57.4 6.5 55 35.6 7.5 56 62.1 6.5 62 33.9 5.5 42 39.6 7.5 40 32.2 11.5 59 57.2 9.5 51 24.4 5.5 50 68.7

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.

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.