Customers arrivals at a checkout counter in a department store per hour have a poisson distribution with parameter λ = 7. calculate the probabilities for the following events.(1) (2 points) exactly seven customers arrive in a random 1-hour period.(2) (4 points) no more than two customers arrive in a random 1-hour period.(3) (4 points) at least three customers arrive in a random 1-hour period

(1)14.9% (2) 2.96% (3) 97.04%

Step-by-step explanation:

Formula for Poisson distribution: where k is a number of guests coming in at a particular hour period.

(1) We can substitute k = 7 and into the formula:

(2)To calculate the probability of maximum 2 customers, we can add up the probability of 0, 1, and 2 customers coming in at a random hours

(3) The probability of having at least 3 customers arriving at a random hour would be the probability of having more than 2 customers, which is the invert of probability of having no more than 2 customers. Therefore:

i think it is 18

step-by-step explanation:

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