In: Math
Customers arrive at a grocery store at an average of 2.1 per
minute. Assume that the number of arrivals in a minute follows the
Poisson distribution. Provide answers to the following to 3 decimal
places.
Part a)
What is the probability that exactly two customers arrive in a
minute?
Part b)
Find the probability that more than three customers arrive in a
two-minute period.
Part c)
What is the probability that at least seven customers arrive in
three minutes, given that exactly two arrive in the first
minute?
question c is not 0.442
Let X denotes the number of customers arrive at a grocery store in a minute.
X ~ Poisson(2.1)
The probability mass function of X is
a) The probability that exactly two customers arrive in a minute is
b) Let Y denotes the number of customers arrive at a grocery store in a 2 minute period.
Y ~ Poisson(2.1*2) or Y ~ Poisson(4.2)
The probability mass function of Y is
The probability that more than three customers arrive in a two-minute period is
c) The probability that at least seven customers arrive in three minutes, given that exactly two arrive in the first minute is
= P( at least 5 customers arrive in two minutes)