Locate a confidence interval based on the question below.

• How did this data help in your decision-making process?
• If you had the choice to make that decision again, would you make the same decision and why?

As a newly hired in a marketing research firm, you are asked to plan and conduct a survey to estimate the percentage of teenagers who would buy a certain product if available. You are also instructed to estimate the per cent within a margin of error no greater than 3% (E=.03).

1. Use the formula n=(z/E)2 ( p q ) to find the sample size n, where z=1.96, and E=.03

Since you have no information about the estimated proportion p you decide to use (0.50.5)

2. Use p = 0.58 and your found n to calculate a 95% confidence interval for the true population proportion p.

3. Justify your decision to use (0.5 x 0.5) in your formula to find n when p is unknown.