Determining Sample Size. In Exercise, use the given data to find the minimum sample size required to estimate a population proportion or percentage.

Airline Seating You are the operations manager for American Airlines and you are considering a higher fare level for passengers in aisle seats. You want to estimate the percentage of passengers who now prefer aisle seats. How many randomly selected air passengers must you survey? Assume that you want to be 95% confident that the sample percentage is within 2.5 percentage points of the true population percentage.

a. Assume that nothing is known about the percentage of passengers who prefer aisle seats.

b. Assume that a recent survey suggests that about 38% of air passengers prefer an aisle seat (based on a 3M Privacy Filters survey).

Step 1 of 4

a) Given error(e) = 2.5%

= 0.025

At 95% confidence level Z=1.96

Assume that p and q are unknown

i.e. p = 0.5, q = 0.5