The fracture strength of a certain type of manufactured glass is normally distributed with a mean of 579 MPa with a standard deviation of 14 MPa. (a) What is the probability that a randomly chosen sample of glass will break at less than 579 MPa? (b) More than 590 MPa? (c) Less than 600 MPa?

Answer 1

Z = (x - mean)/Standard Deviation

Calculate the z scores for the various values. Then look them up in the back of your stats text called something like "areas under normal distribution" to find the probabilities.

I hope this helps.