The mayor is interested in finding a 90% confidence interval for the mean number of pounds of trash per person per week that is generated in the city. The study included 133 residents whose mean number of pounds of trash generated per person per week was 36.1 pounds and the standard deviation was 8.8 pounds. Round answers to 3 decimal places where possible.

a. To compute the confidence interval use a ? z t distribution.

b. With90% confidence the population mean number of pounds per person per week is between and pounds.