Question

the length of an instant message conversation is normally distributed with a mean of 5 minutes and a standard deviation of 0.7 minutes. what is the probability that a conversation lasts longer than 6 minutes?

Answer 1

Answer: 0.922

Explanation:

6-5/0.7= 10/7 or 1.42

Standard normal distribution= .92220

Answer 2

We have mean of 5 and a standard deviation of 0.7 minutes
P(Z > 6 - 5/0.7) = P(Z > 10/7) = 1 - P(Z < 10/7) = 1 - 0.92344 = 0.07656