# 4M Promotion Response A phone company launched an advertising program designed to increase the…

4M Promotion Response

A phone company launched an advertising program designed to increase the number of minutes of long-distance calls made by customers. To get a sense of the benefits of the program, it ran a small test of the promotion. It first selected a sample of 100 customers of the type being targeted by the promotion. This sample of 100 customers used an average of 185 minutes per month of long-distance service. The company then included a special flyer in its monthly statement to those customers for the next two billing cycles. After receiving the promotion, these same customers were using 215 minutes per month. Did the promotion work?

Motivation

(a) Explain why it makes sense for the company to experiment with a sample of customers before rolling this program out to all of its subscribers.

(b) What is the advantage of measuring the response using the same customers? What is the weakness?

Method

Let  denote the number of minutes used by a customer before the promotion, and let  denote the number of minutes after the promotion. Use  for the mean of  (before the promotion) and  for the mean of  (after).

(c) The data on the number of minutes used by a customer during a given month are rather skewed. How does this affect the use of confidence intervals?

(d) Form a new variable, say , that measures the change in use. How can you use the 95% confidence interval for the mean of ?

Mechanics

(e) Form 95% confidence intervals for the mean  of  and the mean  of .

(f) Form the 95% confidence interval for the mean of the difference .

(g) Which of the intervals in parts (e) and (f) is shortest? Is this a good thing? Explain why this interval is far shorter than the others.

Message

(h) Interpret, after appropriate rounding, the confidence interval for  in the context of this problem. Are there any caveats worth mentioning?

(i) If the advertising program is rolled out to 10,000 subscribers in this region, what sort of increase in phone usage would you anticipate?

## Calculate the price of your order

550 words
We'll send you the first draft for approval by September 11, 2018 at 10:52 AM
Total price:
\$26
The price is based on these factors:
Number of pages
Urgency
Basic features
• Free title page and bibliography
• Unlimited revisions
• Plagiarism-free guarantee
• Money-back guarantee
On-demand options
• Writer’s samples
• Part-by-part delivery
• Overnight delivery
• Copies of used sources
Paper format
• 275 words per page
• 12 pt Arial/Times New Roman
• Double line spacing
• Any citation style (APA, MLA, Chicago/Turabian, Harvard)

# Our guarantees

Delivering a high-quality product at a reasonable price is not enough anymore.
That’s why we have developed 5 beneficial guarantees that will make your experience with our service enjoyable, easy, and safe.

### Money-back guarantee

You have to be 100% sure of the quality of your product to give a money-back guarantee. This describes us perfectly. Make sure that this guarantee is totally transparent.

### Zero-plagiarism guarantee

Each paper is composed from scratch, according to your instructions. It is then checked by our plagiarism-detection software. There is no gap where plagiarism could squeeze in.

### Free-revision policy

Thanks to our free revisions, there is no way for you to be unsatisfied. We will work on your paper until you are completely happy with the result.