Question

The rates of on-time flights for commercial jets are continuously tracked by the U.S. Department of Transportation. Recently, Southwest Air had the best reate with 80 % of its flights arriving on time. A test is conducted by randomly selecting 12 Southwest flights and observing whether they arrive on time. (a) Find the probability that exactly 6 flights arrive late.

Answer 1

Solution

Given that ,

p = 0.80

q = 1 - p = 1 - 0.80=0.20

n = 12

Using binomial probability formula ,

P(X = x) = (_n C _x) * p ^x * (1 - p)^{n - x}

P(X = 6) = (₁₂ C ₆) * (0.80)⁶ * (0.20)⁶

^=0.0155

^{probability=0.0155}