Question

A lot of 1000 screws contain 1% with major defects and 5% with minor defects. If 50screws are picked at random and inspected, what are the expected numbers of major and minor defectives?

Answer 1

A lot of 1000 screws contain 1% with major defects and 5% with minor defects. If 50 screws are picked at random and inspected then expected numbers of major and minor defectives would be:

Expected numbers of major defective = $50\times1\%=0.5$

Expected numbers of minor defective = $50\times5\%=2.5$