Refer to Note 1.5. For a logistic model, show that the average estimated rate of change in the response probability as a function of explanatory variable j, adjusting for the others, satisfies 1 n

∑

i

(???? ̂????i∕????xij) = ????̂

j 1

n

∑

i

[ ̂????i(1 − ̂????i)].