Question 1 suppose the lifetime of a refrigerator is normally distributed with a mean of 2500 days and a standard deviation of 1000 days. a) What is the probability that a randomly selected refrigerator will work at least 10 years? (10 pts) b) Describe the sampling distribution of sample mean for a random sample of 625 refrigerators. (10 pts) c) If 625 refrigerators are selected, within what limits would you expect the population mean to lie with probability 0.95? (15 pts) d) If 625 refrigerators are selected, within what limits would you expect the population mean to lie with probability 0.92? (15 pts)