1. Assume that there are n = 400 customers visiting a store every day, and that each cus- tomer spends a random amount of money X.. Furthermore, assume that these amounts are independent and identically distributed with a Uniform (5,55) distribution. (a) (5 points) Provide an approximate distribution for the average daily customer spend- ing (Xn = _ _ _, Xi); specify the distribution's name and parameter values. (b) (5 points) Find an approximate probability that the total daily customer spending exceeds 11, 500. (Hint: use an online probability calculator like this one.)