Quality control. The weight of potato chips in a medium size bag is stated to be 10

ounces. The amount that the packaging machine puts in these bags is believed to have a Normal

model with a mean of 10.2 ounces and a standard deviation of 0.12 ounces.

(2) (a) What fraction of all bags sold are underweight?

(2) (b) Some of the chips are sold in “bargain packs” of 3 bags. What is the probability that none

of the 3 is underweight?

(6) (c) What is the probability that the mean weight of the 3 bags is below the stated amount?

What assumptions are you making? Comment on whether you think these assumptions are valid.

(3) (d) What is the probability that the mean weight of a 24-bag case of potato chips is below 10

ounces?