In Problem 2.4, you used linear regression to describe the relationship between gentamicin efficacy (in terms of the number of bacteria present after treatment C) and the amount of time the level of gentamicin in the blood was above its effective concentration M for dosing intervals of 1–

4 hours. These investigators also used dosing intervals of 6–12 hours.

(The data are in Table D-3, Appendix D.) Does the relationship between C and M depend on dosing schedule? Use multiple regression, and explain your answer.