Answer:
18.88% probability that three or four customers will arrive during the next 30 minutes
Step-by-step explanation:
In a Poisson distribution, the probability that X represents the number of successes of a random variable is given by the following formula:
[tex]P(X = x) = \frac{e^{-\mu}*\mu^{x}}{(x)!}[/tex]
In which
x is the number of sucesses
e = 2.71828 is the Euler number
[tex]\mu[/tex] is the mean in the given time interval.
Average rate of 6.4 per 30 minutes.
This means that [tex]\mu = 6.4[/tex]
What is the probability that three or four customers will arrive during the next 30 minutes?
[tex]P = P(X = 3) + P(X = 4)[/tex]
[tex]P(X = x) = \frac{e^{-\mu}*\mu^{x}}{(x)!}[/tex]
[tex]P(X = 3) = \frac{e^{-6.4}*(6.4)^{3}}{(3)!} = 0.0726[/tex]
[tex]P(X = 4) = \frac{e^{-6.4}*(6.4)^{4}}{(4)!} = 0.1162[/tex]
[tex]P = P(X = 3) + P(X = 4) = 0.0726 + 0.1162 = 0.1888[/tex]
18.88% probability that three or four customers will arrive during the next 30 minutes