Could I have some assistance with the following question:

The number of machine failures per month in a certain plant has a Poisson distribution with mean equal to 3. Present facilities at the plant can repair 4 machines per month. If any additional machines fail then they are repaired by an outside contractor.

a) Use Matlab to find the probability, on a given month, that the contractor is required to work in the plant. Give your answer to three decimal places.

b) The cost (in thousands of dollars) to the plant of machine failures can be approximated as:

X = 17+5*Y+Y^2

Find (to one decimal place) the expected cost of machine failures per month (in thousands of dollars).

For part a I've tried 1-poisscdf(3,3) because I think it is the probability of P(X>=4) which is 1-P(X<=3),

for the second part I am very lost.

Any help would be very much appreciated.