The breaking strength (in pounds) of a certain new synthetic is normally distributed, with a mean of 160 pounds and a variance of 16. The material is considered defective if the breaking strength is less than 152 pounds. What is the probability that a randomly selected piece of material will be defective? Please round the answer to the nearest thousandth, if necessary.
A) 0.023
B) 0.159
C) 0.977
D) 0.999
E) 0.001

Question

Quizplus · Accepted Answer

The Z-score for 152 pounds is (152-160)/4 = -2. The probability of a Z-score being less than -2 is approximately 0.023.

The Breaking Strength (In Pounds) of a Certain New Synthetic