Could you please explain me how to do the calculation to get the answer from the exercise below?

Given an average service rate of twelve customers per hour, what is the probability the business can handle all the customers when the average arrival rate is ten customers per hour? Use the Poisson distribution to calculate the probabilities for various customer arrivals. Number of Arrivals P (x for T = 1 hr) Cumulative (x) Probability O .000 000 .000 001 .002 003 W .008 .010 . 019 .029 .038 .067 .063 .130 .090 .220 CO .113 333 .125 .458 10 .125 .583 11 .114 .697 12 .095 .792 Thus, the business can handle 12 customers per hour about 79% of the time, when the average arrival rate is 10 customers per hour.AT AT)E Pyr) = S where A = average customer arrivals in time period T e = 2.71828 (natural log base) T = time period in hours (usually assumed to bel) z! = g factorial =2z 1)(z2)...(1)