Customers arrive at a bank tellers booth at a rate of 2 per

Customers arrive at a bank teller\'s booth at a rate of 2 per minute. What is the probability (to four decimal places) that 4 customers will arrive at the bank teller\'s booth within the next minute (assume a Poisson distribution)

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 = 4 ) = e ^-2 * 2^4 / 4! = 0.0902