A city built a new parking garage in a business district. For a random sample of 100 days, daily fees collected averaged $2,500, with a standard deviation of $500. Construct a 90% confidence interval estimate of the mean daily income this parking garage generates. Show all work. Just the answer, without supporting work, will receive no credit.
(Show all work. Just the answer, without supporting work, will receive no credit)
A combination lock uses three distinctive numbers between 0 and 49 inclusive. How many different ways can the sequence of three numbers be selected?