1)At a fire station, each call out is classified as either genuine or false. Call outs occur at random times. On average there are 2 genuine calls in a week, one false call in a 2 week period. Calculate the probability that there are fewer than 6 genuine calls in a 2 week period.

(Ans:0.440)

my ans is 0.785.. This is my working.X~Po(4), P(X<=5) Why is it wrong?