Suppose a geyser has a mean time betwen eruptions of 83 minutes. Let the interval of time between the erupitons be normally distributed with standard deviation 24 minutes.
a. what is the probability that a randomly selected time interval between eruptions is longer than 94 minutes?
b. what is the probability that a random sample of 10 time intervals between eruptions has a mean longer than 94 minutes?
c. what is the probability that a random sample of 30 time intervals between eruptions has a mean longer than 94 minutes?