Assume a geyser has a mean time betwen eruptions of 96 minutes. Let interval of time between the erupitons be normally distributed with standard deviation 29 minutes.
a. what is the probability that a randomly selected time interval between eruptions is longer than 108 minutes?
b. what is the probability that a random sample of 9 time intervals between eruptions has a mean longer than 108 minutes?
c. what is the probability that a random sample of 39 time intervals between eruptions has a mean longer than 108 minutes?
d. the probability that the mean of a random sample of 39 time intervals is more than 108 miniutes is approximatley what?