1. A local radio station maintains a very popular phone service, which provides callers with current weather reports. The incoming calls have a Poisson distribution with an average of 5 calls for each 15 minute-period. Ifx= time between calls, then the probability of receiving four or fewer calls in the next 15 minutes is:
2. Suppose thatxis a binomial random variable withn= 100 andp= 0.18. Employ the normal approximation to findP(15 <=x <=21).
3. A coin is flipped 14 times. Using the normal distribution, calculate the probability of observing either 4, 5, or 6 heads
4. A statistics class is composed of 60 percent females. If 15 students are selected randomly, what is the probability that this group will include either 8, 9, 10, or 11 females? Use the normal distribution.