On a particular day, 112 of 280 passengers on a particular DTW-LAX flight used the e-ticket check-in kiosk to obtain boarding passes. In a random sample of eight passengers, what is the probability that four will have used the e-ticket check-in kiosk to obtain boarding passes.

Answer :

0.2322

Step-by-step explanation:

Proportion, p of those who used e - ticket to get boarding pass = 112 / 280 = 0.4

p = 0.4

1 - p = 1 - 0.4 = 0.6

Number of samples, n = 8

P(x = 4)

Using the binomial probability formula :

P(x =x) = nCx * p^x * (1 - p)^(n - x)

P(x = 4) = 8C4 * 0.4^4 * 0.6^4

P(x = 4) = 70 * 0.0256 * 0.1296

P(x = 4) = 0.2322432

P(x = 4) = 0.2322

tangent

step-by-step explanation: