A Dry Cleaner Has a Single Drive-Thru Window for Customers

question 70

Essay

A dry cleaner has a single drive-thru window for customers.The arrival rate of cars follows a Poisson distribution, while the service time follows an exponential distribution.The average arrival rate is 16 per hour and the average service time is three minutes.
(a)What is the average number of cars in the line?
(b)What is the average time spent waiting to get to the service window?
(c)What percentage of time is the dry cleaner's drive-thru window idle?
(d)What is the probability there are more than 2 cars at the drive-thru window?

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Definitions:

Sponge

A simple aquatic creature with a porous body, or a soft, absorbent material used for washing and cleaning.

Type II Alveolar Cell

is a cell in the alveoli of the lungs that produces surfactant to reduce surface tension and prevent lung collapse.

Surfactant

A substance that reduces surface tension, in the lungs it prevents the collapse of alveoli during exhalation.

Gas Exchange

The biological process through which gases (like oxygen and carbon dioxide) are transferred between the bloodstream and the environment.