# math

The breaking strength (in pounds) of a certain new synthetic is normally distributed, with a mean of 167 and a variance of 9. The material is considered defective if the breaking strength is less than 158 pounds. What is the probability that a single, randomly selected piece of material will be defective? (Give the answer to two decimal places.)
1 %

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1. Z = (score-mean)/SD

Variance = SD^2

Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion/probability related to the Z score.

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