Question

The table below contains the amount that a sample of nine customers spent for lunch​ ($) at a​ fast-food restaurant. Complete parts a and b below. 4.33 5.14 5.67 6.31 7.36 7.67 8.48 8.79 9.18

a. Construct a 99​% confidence interval estimate for the population mean amount spent for lunch at a​ fast-food restaurant, assuming a normal distribution. The​ % confidence interval estimate is from ​$ nothing to ​$ nothing. ​(Round to two decimal places as​ needed.)

b. Interpret the interval constructed in​ (a).

Choose the correct answer below.

A. We have 99​% confidence that the mean amount in dollars spent for lunch at the​ fast-food restaurant for the sample is contained in the interval.

B. 99​% of the sample data fall between the limits of this confidence interval.

C. The mean amounts in dollars spent for lunch at the​ fast-food restaurant of 99​% of all samples of the same size are contained in the interval.

D. We have 99​% confidence that the population mean amount in dollars spent for lunch at the​ fast-food restaurant is contained in the interval.

Answer 1

The statistical software output for this problem is:

Hence,

a) 99% confidence interval:

From $ 5.07 to $ 8.91

b) We have 99​% confidence that the population mean amount in dollars spent for lunch at the​ fast-food restaurant is contained in the interval.

Option D is correct.