b) The time-averaged concentration over a time period T is given by: b f= (b - a ) If (t ) at a T 1 1 T S m=- [mdt = [1- exp(- kt) ]dt {T - - [1- exp(- KT)]} T 0 KT k Here T = 1/k so m = (S/k)/e = S/(k*e) = S*T/e = 1.84*S