In an effort to estimate the mean amount spent per customer for dinner at a major Atlanta restaurant, data were collected from 64 randomly selected customers. The sample mean was calculated as $28.80 with a sample standard deviation of $4. We wish to develop a 91% confidence interval for the mean amount spent per customer for dinner at this restaurant. Assume that the standard deviation of the amounts spent by ALL customers is $4.30. ts a) What is the population of interest? What is the variable of interest? ts b) What was the sample size? S c) Find the 91% confidence interval. Note: we assume the standard deviation of the amounts spent by ALL customers is $4.30. d) Based upon the above confidence interval, can it be concluded - with at least 91% confidence - that the average customer spends more than $25 at the restaurant? Yes or No (circle one) AND WHY