1. Whether a customer at a carry-out restaurant leaves a tip is a random variable. The probability that a customer leaves a tip is 0.42. The probability that one customer leaves a tip is independent of whether another customer leaves a tip. Let leaving a tip represent a success and not leaving a tip represent a failure.

1. Does this problem describe a discrete or continuous random variable?
2. What kind probability distribution fits the random variable described in this problem?
3. What is the probability that a customer does not leave a tip?
4. Calculate the mean and variance of this distribution.
5. What is the probability that on a day with 100 customers, exactly 50 of them leave a tip?