SOLUTION: I need help with my last homework question that I can't seem to figure out, heres the question.. Cars arrive at Kenny's car wash at a rate of 3.4 per half hour. What is the prob

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Question 539681: I need help with my last homework question that I can't seem to figure out, heres the question..
Cars arrive at Kenny's car wash at a rate of 3.4 per half hour. What is the probability that in any given half hour atleast 3 cars arrive in this carwash?
work shown please and thank you.
Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website!
Cars arrive at Kenny's car wash at a rate of 3.4 per half hour. What is the probability that in any given half hour atleast 3 cars arrive in this carwash?
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Poisson Problem
P(x>=3) = 1 - P(0< x < 3)
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u = 3.4
P(0< x <3) = summation from x = 0 to 3 of [(e^-u*u^x)/x!]
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= [(e^-3.4*3.4^0)/0!] + [(e^-3.4*3.4^1)/1!] + [(e^-3.4*3.4^2)/2!]
+ [(e^-3.4*3.4^3)/3!]
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Using a TI-84 I get P(0 ========
So P(x>=3) = 1-0.5584 = 0.4416
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Cheers,
Stan H.
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