Data were collected on the amount spent by fi4 customers for lunch at a major Houston restaurant. These data are contained in the file Houston. Based upon past studies the population standard deviation is known with = $. Click on the datafile logo to reference the data. DATA I 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. $ to 0= Icon Key