10.2 Backpack weights. In Exercise 9.46, we studied backpacks and

back problems. Overall, females are more likely to have back

problems than are males: 44% versus 18%. In a multiple logistic

regression model that adjusts for BackpackWeight and BodyWeight,

the odds ratio of back problems for females versus males is 4.24.

a. Based on the percentages, compute the odds for having

back problems for both females and males.

b. Using the odds from (a), find the odds ratio for having back

problems for females versus males.

c. Explain why this odds ratio differs from the given odds

ratio of 4.24.