The Utah County Telephone Company claims in its 2022 annual report that "the typical customer spends $60 per month on telephone service." A sample of 12 customers revealed the following amounts spent per month: $64, $66, $64, $66, $59, $62, $67, $61, $64, $58, $54, $66.
(a) What is the value of the population mean?
(b) What is the value of the sample estimate?
(c) Develop a 90 percent confidence interval for the population mean.
(d) What is the margin of error?
(e) Interpret the confidence interval in part c.
(f) Is the company's claim that the "typical customer" spends $60 per month reasonable? Justify your answer. Only stating yes or no sufficient. Provide statistical evidence.
Note: Use Excel (Commands, Insert Function or Data Analysis) to compute the descriptive statistics necessary to construct the confidence interval in Question 2. You should not compute the necessary descriptive statistics by hand. Use the Excel functions. It will save you time.