A manager of a local drugstore is projecting next month's sales for a particular cosmetic line. She knows from historical data that sales follow a continuous uniform distribution with a lower limit of $2,500 and an upper limit of $5,000. a. What are the mean and the standard deviation for this continuous uniform distribution? b. What is the probability that sales exceed $4,000? c. What is the probability that sales are between $3,200 and $3,800?