Hi, I am trying to use proc power to determine sample size for a direct mail test. I want to know how many people I need send package B (as opposed to package A) in order to have a confidence level of .05 and power of .80. For package B to be successful it will need to increase the response rate from an estimated .03 which is what we expect from package A to .035. I know I will be sending 100,000 people package A as a control and want to use proc power to determine how many people should be sent package B. Thanks