Question

A manufacturer of batteries knows that 10% of the batteries produced by a particular production line are defective. A sample of 200 batteries is removed for testing.

a) What is the probability that exactly 20 batteries in the sample are defective?
[2 marks]
b) What is the probability that at least 20 batteries in the sample are defective?
[7 marks]

Answer 1

I think you need only an answer without expanation so let's start.
a)
`P = (200!)/(180!x20!) * 0,1^(20)*0,9^(180) = 0.093636`
b)
`Probability = 0.5 + (1)/(2) (0.093636) = 0.54682`