Question 615359
I have lost here with 2 different formula it's likely the same for me ,f(x) = n nCr x p^x(1 - p)^n-x or the Discrete population Probability D??which one is corrector and why? 
Because not all airline passengers show up for their reserved seat, an airline sells 125 tickets for a flight that holds only 120 passengers. The probability that a passenger does not show up is 0.10, and the passengers behave independently. 
a)What is the probability that every passenger who shows up can take the flight?
P(x <= 120) = binomcdf(125,0.90,120) = 0.9961
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b)What is the probability that the flight departs with empty seats?
P(x > = 5) = 1 - binomcdf(125,0.1,5) = 0.9886
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c)What is the probability that the flight departs with exactly 5 empty seats?
P(x = 115)= 125C115*(0.9)^115*(0.1)^5 =  0.0970
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Cheers,
Stan H.
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