Biscuits are sold in packets of 18. There is a constant probability that any biscuit is broken, independently of other biscuits. The mean number of broken biscuits in a packet has been found to be 2.7. Find the probability that a packet contains between 2 and 4 (inclusive) broken biscuits.
Please help me solve the question above.. I'm totally confused. An explanation will be appreciated!
Let random selection of broken biscuit follows Binomial distribtion.
mean of binomial distribution= np
Probability of r broken biscuits.
probability that a packet contains between 2 and 4 (inclusive) broken biscuits = P(x=2)+P(x=3)+P(x=4)