Question

A company claims that 99% of its cereal boxes have at least as much cereal by weight as the amount stated on the box.

a. At a quality control checkpoint, one box out of a random sample of ten boxes falls short of its stated weight. What is the probability of this happening due to chance variation in box weights?
b. Suppose three of ten boxes fail to have the claimed weight. What would you conclude? Explain why.

Answer 1

a. 1%.
b. The chances would be .01% or 1 in 10,000. Due to the high improbability of this, I would conclude that less than 99% of the boxes contain the weight stated on the box.