A plan to increase shoppers in a dense downtown area requires building a new parking garage. This public project will in part be funded by the parking fees collected. Based on another parking garage data, the plan estimates that during 45 days the garage would collect a mean of $134 daily fees with a standard deviation of $15 (treat this as o). (a) State the parameter our confidence interval will estimate. (b) What type of an interval can be constructed for this parameter? Why? (c) Find the mean and the margin of error for a 90% confidence interval. (d) Finally, put all the pieces together for an 90% confidence interval for the mean doctor visit amount. (you may leave your answer in form.)