A company that bakes chocolate chip cookies averages 52 choc

A company that bakes chocolate chip cookies averages 5.2 chocolate chips per cookie. Assume that the number of chocolate chips per cookie follows the Poisson distribution. What is the probability that a randomly selected cookie will contain one or two chocolate chips?

Please explain answer with formula.

Solution

Possion Distribution
PMF of P.D is = f ( k ) = e- x / x!
Where   
= parameter of the distribution.
x = is the number of independent trials
P( X < 2) = P(X=1) + P(X=0) +
= e^-5.2 * 3 ^ 1 / 1! + e^-5.2 * ^ 0 / 0! +   
= 0.0342

P( X > = 2 ) = 1 - P (X < 2) = 0.9658