Question 519256
a company minibus has 7 passenger seats and on a routine run it is estimated that any passenger seat will be filled with probability 0.42. 
i. What is the mean and variance of the binominal distribution of the number of passengers on a routine run?
mean = np = 7*0.42 = 2.94
variance = npq = 1.71
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ii. Calculate the probability that on a routine run, there will be at least three passengers.
P(3<= x <=7) = 1 - P(0<= x <=2) = 1 - binomcdf(7,0.42,2) = 0.6229
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Cheers,
Stan H.