Direct mail advertisers send solicitations ("junk mail") to thousands of potential customers in the hope that some will buy the company's product. The response rate is usually quite low. Suppose a company wants to test the response to a new flyer and sends it to 1150 people randomly selected from their mailing list of over 200,000 people. They get orders from 114 of the recipients.

Question

Direct mail advertisers send solicitations​ ("junk mail") to thousands of potential customers in the hope that some will buy the​ company's product. The response rate is usually quite low. Suppose a company wants to test the response to a new flyer and sends it to 1150 people randomly selected from their mailing list of over​ 200,000 people. They get orders from 114 of the recipients.

Create a 90​% confidence interval for the percentage of people the company contacts who may buy something.

Ms. H · Answer

n = 1150 x = 114 p = x/n p = 114/1150 = 0.099 z critical value = ____ (Then, I got this formula from the question in the 'Related Questions' below. I hope this helps.) E = za/2 *sqrt((p (1-p)/)/n))