Question: The Warren County Telephone Company claims in its annual report that "the typical customer spends $70 per month on local and long-distance service." A sample of 12 subscribers revealed the following amounts spent last month.
Amounts Spent Last Month:
$64
$57
$59
$68
$60
$65
$69
$56
$58
$56
$55
$56
a) What is the point estimate of the population mean? (Round your answer to 3 decimal places)
b) Determine the 99% confidence interval for the population mean. (Round your answer to 2 decimal places)
Note: Confidence interval is between $ and $.
c) Is the company's claim that the "typical customer" spends $70 per month reasonable?