A Major Department Store Chain Is Interested in Estimating the Average

Multiple Choice

A major department store chain is interested in estimating the average amount its credit card customers spent on their first visit to the chain's new store.Fifteen credit card accounts were randomly sampled and analysed with the following results: $\bar { X }$ = $50.50 and S = 20.
-Construct a 95% confidence interval for the average amount its credit card customers spent on their first visit to the chain's new store in the mall assuming that the amount spent follows a normal distribution.

A) $50.50 ± $11.00
B) $50.50 ± $10.12
C) $50.50 ± $9.09
D) $50.50 ± $11.08