statistics

Home Security Systems: In 2008, 17% of American homes were protected by a home security system. A marketing firm wanted to estimate the proportion of protected homes today. Questions: a) How large a sample is needed, if they want to be 95% confident, that their estimate is within two percentage points of the true percentage of American homes protected by a home security system using the data in 2008? Use the rounding rule for sample size. Show work or explain how you obtained your answer. b) How large a sample is necessary if nothing is known about the proportion of American homes protected by a home security system? Use the rounding rule for sample size. Show work or explain how you obtained your