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 1160 people randomly selected from their mailing list of over 200,000 people. They get orders from 144 of the recipients. Create a 90% confidence interval for the percentage of people the company contacts who may buy something.

The 90% confidence interval for the percentage of people the company contacts who may buy something is between 10.82% and 14%

Step-by-step explanation:

In a sample with a number n of people surveyed with a probability of a success of , and a confidence level of , we have the following confidence interval of proportions.

In which

z is the zscore that has a pvalue of .

For this problem, we have that:

90% confidence level

So , z is the value of Z that has a pvalue of , so .

The lower limit of this interval is:

The upper limit of this interval is:

The 90% confidence interval for the percentage of people the company contacts who may buy something is between 10.82% and 14%

step-by-step explanation: