Suppose R is the percent of maximum response for a dose of x mg of a certain drug and is given by the formula

R=100/1+100e^−0.07x
What dose corresponds to a 50% response rate?

Suppose the minimum effective response is 17% and the maximum safe response is 71%.
What is the smallest dose that should be administered?

What is the largest dose that should be administered?

#1. Just solve 100/(1+100e^(−0.07x)) = 50

x = 65.788

#2. smallest: 100/(1+100e^(−0.07x)) = 17
largest: 100/(1+100e^(−0.07x)) = 71