Suppose a geyser has a mean time between eruptions of 70 minutes. let the interval of time between the eruptions be normally distributed with standard deviation 18 minutes.
(a) what is the probability that a randomly selected time interval between eruptions is longer than 79 minutes?
(round to four decimal places as needed.)
(b) what is the probability that a random sample of 88 time intervals between eruptions has a mean longer than 79 minutes?
(round to four decimal places as needed.)
(c) what is the probability that a random sample of 27 time intervals between eruptions has a mean longer than 79 minutes?
(round to four decimal places as needed.)

Step-by-step explanation:

Let X be the geyser mean time between eruptions of 70 minutes.

X is N (70, 19)

a)

b) Sample size =88. Std error =

c) For sample size =27, std error =

P(X>79) = P(Z>2.46) =0.5-0.4931=0.0069

66.666666667%

step-by-step explanation:

divide 150 by 100

divide 100 by 1.5

there you go!

decreased by 33.333333334%

step-by-step explanation:

a cube has 6 sides

the probability of getting 5 on the first cube is 1/6 since only one side of the cube has 5 on it.

there are 3 sides of the cube with even number on it [2,4,6]

therefore the probability of getting even number is 3/6

for both events to happen together, the probability would be

1/6 x 3/6 = 12/36

which simplifies to 1/12