Answer: The value of X is 26.
Explanation: The explanation is in the image.
If X is a random variable representing the number of children that end up having light-colored eyes, then X follows a binomial distribution with success probability p = 0.25 and number of trials n = 5.
The variance of a binomial distribution with these parameters is n p (1 - p), so the variance in this case would be
5 • 0.25 • (1 - 0.25) = 0.9375 ≈ 0.9
Since the plane descends 1,300 feet per minute it would descend 19,500 feet after 15 minutes (1,300 x 15 = 19,500) Subtract this from the plane's initial altitude 32,000 and the new altitude will be 12,500. (32,000-19,500=12,500)
The height is 6tan(60)=10.39 then plug that in to trapezoid area formula
(11+6+15)/2*10.39=166.24