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 1170 people randomly selected from their mailing list of over​ 200,000 people. They get orders from 150 of the recipients. Use this information to complete parts a through d.
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Part 1
​a) Create a 90​% confidence interval for the percentage of people the company contacts who may buy something.
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​(Round to one decimal place as​ needed.)
Part 2
​b) Explain what this interval means.
A.
The company is 90​% confident that the percentage of people who will respond to the flyer falls within the confidence interval bounds.
B.
The company is 90​% confident that the probability a randomly sampled person will respond to the flyer falls within the confidence interval bounds.
C.
The values for the interval bounds should be subtracted from 90​% to obtain the​ company's true confidence level.
D.
The company is 90​% confident that the percentage of people who will not respond to the flyer falls within the confidence interval bounds.
Part 3
​c) Explain what ​"90​% ​confidence" means.
A.
About 90​% of all random samples of size 1170 will produce intervals that contain the true proportion of people who will respond to the new flyer.
B.
About 90​% of all randomly sampled people will respond to the new flyer.
C.
About 90​% of all random samples will produce intervals that contain the true proportion of people who will respond to the new flyer.
D.
About 90​% of all random samples of size 1170 will produce intervals that do not contain the true proportion of people who will respond to the new flyer.
Part 4
​d) The company must decide whether to do a mass mailing. The mailing​ won't be​ cost-effective unless it produces at least a 6​% return. What does your confidence interval​ suggest?
A.
Do not do the mass mailing.
B.
Do the mass mailing.