Question

The owner of a restaurant that serves continental food wants to study characteristics of his customers. He decides to focus on two variables: the amount of money spent by customers and whether customers order dessert. The results from a sample of 60 customers are as follows: • Amount spent: X=$38.54, S= $7.26 • 18 customers purchased dessert. a. Construct a 95% confidence interval estimate of the population mean amount spent per customer in the restaurant.

Answer 1

Confidence interval:

$\=x\pm z\frac{s}{\sqrt{n}}$

z is the chosen Z-value (1.96 for 95% from t-table)

$38.54-(1.96)(\frac{7.26}{\sqrt{60}})<\mu<38.54+(1.96)(\frac{7.26}{\sqrt{60}})$

$36.70<\mu<40.38$

95% confidence interval is (36.70, 40.38)