Data were collected on the amount spent by 64 customers for lunch at a major Houston restaurant. These data are contained in the file named Houston.

Data were collected on the amount spent by 64 customers for lunch at a major Houston restaurant. These data are contained in the file named Houston. Based upon past studies the population standard deviation is known with σ = $15.

Click on the webfile logo to reference the data.

Round your answers to two decimal places. Use the critical value with three decimal places.

a. At 99% confidence, what is the margin of error?

b- Develop a 99% confidence interval estimate of the mean amount spent for lunch.