Question

When pieces of wood first arrive at the baseball bat factory, they are placed on a lathe and shaped into the form of a baseball bat. The company has a few dozen lathes in operation at all times. An engineer working at the facility records how many times per week a lathe breaks down and needs to be repaired. Assume that Y = # of lathe repairs needed in one week and that Y is Poisson with λ = 3.3.

(a) What is the probability that exactly 5 lathe repairs will be needed next week?

(b) What is the standard deviation of the number of lathe repairs?

Answer 1

a)

b)

If X ~ P (λ)
Var(X) = λ

Standard deviation = sqrt(3.3) = 1.817