Question

A study of the checkout lines at the Safeway Supermarket in the South Strand area revealed that between 4 and 7 P.M. on weekdays there is an average of four customers waiting in line. What is the probability that you visit Safeway today during this period and find:

a. No customers are waiting?
b. Four customers are waiting?
c. Four or fewer are waiting?
d. Four or more are waiting?

Answer 1

Explanation:

Given that a study of the checkout lines at the Safeway Supermarket in the South Strand area revealed that between 4 and 7 P.M. on weekdays there is an average of four customers waiting in line.

Let X be the number of customers waiting in line

X is Poisson with parameter = 4

the probability that you visit Safeway today during this period and find:

a. No customers are waiting

`P(X=0) = 0.018316`

b. Four customers are waiting?

`=P(x=4) =0.193567`

c. Four or fewer are waiting?

=
`P(X\leq 4) = 0.628837`

d. Four or more are waiting

=
`P(X\geq 4)=0.56653`