A research firm wants to be 90% confident that a population percentage has been estimated to within 3 percentage points. The research manager calculates the necessary sample size with 0.5 as his estimate of the population proportion.
A new business school graduate who has just joined the firm questions the research manager further, and they agree that the population proportion is no more than 0.3. If interviews cost $10 each, how much money has the new graduate just saved the company?