Question

A survey of several 10 to 11 year olds recorded the following amounts spent on a trip to the mall:

$18.41,$18.46,$17.83$⁢18.41,$⁢18.46,$⁢17.83

Construct the 99% confidence interval for the average amount spent by 10 to 11 year olds on a trip to the mall. Assume the population is approximately normal.

Step 1 of 4:

Calculate the sample mean for the given sample data. Round your answer to two decimal places.

Step 2 of 4:

Calculate the sample standard deviation for the given sample data. Round your answer to two decimal places.

Step 3 of 4:

Find the critical value that should be used in constructing the confidence interval. Round your answer to three decimal places.

Step 4 of 4:

Construct the 99% confidence interval. Round your answer to two decimal places.

Answer 1

18.41	0.18	0.0324
18.46	0.23	0.0529
17.83	-0.40	0.1600

Refer t-table or use excel function "=T.INV.2T(0.01,2)" to find the critical value of t.