1 let z be a standard normal random variable with mean 0

Question

1) Let Z be a standard normal random variable with mean = 0 and standard deviation = 1. Us the normal table to find the following answers.

a) P(0 < Z < 0.92)

b) P(-1.22 < Z < 0.92)

c) Find the value Z₀ such that P(0< Z < Z₀)= 0.4901.

2) On a typical weekend afternoon, the travel time from GWU to Dulles airport follows a normal distribution with a mean of 45 minutes and a standard deviation of 4 minutes.

a) What is the probability that the travel time is between 45 and 50 minutes?

b) What is the probability that the travel time is more than 60 minutes?

Find the value x₀ such that the probability it takes less than x₀ minutes to get from GWU to Dulles is 0.99.