LP Example #5 The marketing group for a cell phone manufacturer plans to conduct a telephone survey to determine consumer attitudes toward a new cell phone. They need to contact at least 100 young males, 150 older males, 120 young females, and 200 older females. It costs $1 to make a daytime phone call and $1.50 to make an evening phone call. The table below shows the likelihood of a given customer type answering each phone call. Who Answers? Evening Calls Young Male 20% 30% Older Male Young Female Older Female No Answer Daytime Calls 10% 15% 20% 35% 20% 20% 25% 5% Because of limited evening staffing, at most one-third of phone calls placed can be evening phone calls. LP Example #5 (Cont'd) Question: How should the marketing group conduct the telephone survey so as to meet the sample size requirements at the lowest possible cost