Hoping to attract more shoppers downtown, a city builds a new public parking garage in the central business district. The city plans to pay for the structure through parking fees. For a random sample of 44 weekdays, daily fees collected averaged $12,600 with a standard deviation of $1500.

a) What assumptions must you make in order to use these statistics for inference?

b) Find a 90% confidence interval for the mean daily income this parking garage will generate.

c) Explain in context what this confidence interval means.

d) Explain what 90% confidence means in this context.

e) The consultant who advised the city on this project predicted that parking revenues would average $12,800 per day. Based on your confidence interval, what do you think of the consultant’s prediction? Why?