Question

Customers arrive at a supermarket check-out counter with an average arrival rate of 9 customers per hour. Answer questions 8–10 using the preceding information and modeling this situation as a Poisson distribution.

8. What is the probability of less than 5 customers arriving at the supermarket check-out counter in a given 1-hour period?

a) 0.054 b) 0.446 c) 0.359 d) 0.612

9. What is the probability of exactly 12 customers arriving at the supermarket check-out counter in a given 1-hour period?

a) 0.262 b) 0.044 c) 0.073 d) 0.189

10. What is the probability of no less than 12 customers arriving at the supermarket check-out counter in a given 1-hour period?

a) 0.115 b) 0.197 c) 0.381 d) 0.686

Answer 1

Solution:

we have given that the average arrival rate of customers is 9 customers per hour.

i.e.,

Therefore, the probability distribution of Poisson distribution is given by

8) P(less than 5 customers arriving at the supermarket check-out counter in a given 1-hour period)

9) P(exactly 12 customers arriving at the supermarket check-out counter in a given 1-hour period)

10) P(no less than 12 customers arriving at the supermarket check-out counter in a given 1-hour period)