The actual weights of bag of pet food are normally distributed.The mean of the weights is 50.0 lb,with a standard deviation of 0.2 lb.

Question

A)About what percent of bags of pet food weigh less than 49.8 lb?

Answer 1

z=(X-μ)/σ
=(49.8-50)/0.2
=-1
Look up the probability table normal distributions for z=-1, which should give around 16%.

Answer 2

The breaking strength (in pounds) of a certain new synthetic is normally distributed, with a mean of 170 and a variance of 4. The material is considered defective if the breaking strength is less than 166 pounds. What is the probability that a single, randomly selected piece of material will be defective?