Maths Probability Tutorial 9- Binomial Probability Examples

Test Your Skills

A) Experience has shown that 1/200 of all CDs produced by a certain machine are defective. If a quality control technician randomly tests twenty CDs, compute each of the following probabilities:

• P(exactly one is defective)

• P(half are defective)

• P( no more than two are defective)

B) After studying a couple’s family history, a doctor determines that the probability of any child born to this couple having a gene for disease X is 1 out of 4. If the couple has three children, what is the probability that exactly two of the children have the gene for disease X?

(A) 14/45
(a) .024 (b) .336 (c) .664