QUESTION EIGHT:

Suppose that a company owns 400 computers. Each computer has an 11% probability of not working. Suppose we randomly select 20 computers. What is the probability that more than 2 will not work properly?

QUESTION NINE:

A reputed school when purchasing large shipments of dry erase markers for all its branches. it follows this acceptance-sampling plan. It randomly selects and tests 40 markers, then accept the whole batch if there are less than two found to be not working.

A) If a shipment has a 2.5% defective rate, find the probability that the school purchases the whole batch of markers.

B) If the school purchases 2000 markers, what are the expected number of defective markers?