The probability that Pete will catch fish when he goes fishing is .88. Pete is going to fish 3 days next week. Define the random variable x to be the number of days Pete catches fish. The variance of the number of days Pete will catch fish is
A) 0.56.
B) 0.88.
C) 2.64.
D) 0.3168.

Question

Quizplus · Accepted Answer

The variance of a binomial distribution is given by the formula $ \sigma^2 = np(1-p) $, where $ n $ is the number of trials, $ p $ is the probability of success on each trial. Here, $ n = 3 $ (days) and $ p = 0.88 $, so the variance $ \sigma^2 = 3(0.88)(1-0.88) = 3(0.88)(0.12) = 0.3168 $.

The Probability That Pete Will Catch Fish When He Goes