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
The boat travels 501 miles in 3 weeks.
Step-by-step explanation:
Things I notice about this problem:
- "Difference" indicates subtraction.
- When a problem simply says "a number," I replace it with a variable.
It is written out like this: 
.
Since there are four suits, with each having a 4 and 5, we have 2+2+2+2=2*4=8
