# math

posted by .

The breaking strength (in pounds) of a certain new synthetic is normally distributed, with a mean of 173 and a variance of 9. The material is considered defective if the breaking strength is less than 167 pounds. What is the probability that a single, randomly selected piece of material will be defective?

• math -

Z = (score-mean)/SD

variance = √SD

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.

## Similar Questions

1. ### algebra

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 161 pounds. What is the probability …
2. ### MATH

The breaking strength (in pounds) of a certain new synthetic is normally distributed, with a mean of 175 and a variance of 9. The material is considered defective if the breaking strength is less than 166 pounds. What is the probability …
3. ### math

The breaking strength (in pounds) of a certain new synthetic is normally distributed, with a mean of 172 and a variance of 4. The material is considered defective if the breaking strength is less than 168 pounds. What is the probability …
4. ### math

The breaking strength (in pounds) of a certain new synthetic is normally distributed, with a mean of 173 and a variance of 9. The material is considered defective if the breaking strength is less than 164 pounds. What is the probability …
5. ### 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 …
6. ### Statistics

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 …
7. ### Algebra

The breaking strength (in pounds) of a certain new synthetic is normally distributed, with a mean of 167 and a variance of 4. The material is considered defective if the breaking strength is less than 163 pounds. What is the probability …
8. ### math

The breaking strength (in pounds) of a certain new synthetic is normally distributed, with a mean of 145 and a variance of 25. The material is considered defective if the breaking strength is less than 134.5 pounds. What is the probability …
9. ### math

The breaking strength (in pounds) of a certain new synthetic is normally distributed, with a mean of 165 and a variance of 9. The material is considered defective if the breaking strength is less than 157.8 pounds. What is the probability …
10. ### Math

The breaking strength (in pounds) of a certain new synthetic is normally distributed, with a mean of 125 and a variance of 25. The material is considered defective if the breaking strength is less than 113.5 pounds. What is the probability …

More Similar Questions