A factory produces light bulbs, of which 10% are defective. Each box contains 10 bulbs, and a quality control inspector randomly samples bulbs. Find the probability distribution of the number of defective bulbs in the selection.
b) Find the probability that a box contains exactly 2 defective bulbs.
Find the probability that a box contains at least one defective bulb.
Find the probability that a box contains at most three defective bulbs.
Find the expected (mean) and variance.