You are studying survival times for mice given a drug at one of three doses (Low, Medium, or High). You define two dummy variables: X1 = 0 if Low, 1 if Medium, 1 if High X2 = 0 if Low, 0 if Medium, 1...

You are studying survival times for mice given a drug at one of three doses (Low, Medium, or High). You define two dummy variables:

X1 = 0 if Low, 1 if Medium, 1 if High

X2 = 0 if Low, 0 if Medium, 1 if High

(a) With these definitions, write the expressions for the mean survival at each dose.

(b) How would you express the differences between Medium and Low? High and Medium? High and Low?

(c) If your focus was on the impact of each successively higher dose, would this be more convenient than reference cell coding?