According to the National Telecommunication and Information Administration, 56.5% of U.S.
Households owned a computer in 2001. What is the probability that of three randomly selected U.S.
Households at least one owned a computer in 2001?
A) 18.0%
B) 56.5%
C) 43.5%
D) 82.0%
E) 91.8%

Question

Quizplus · Accepted Answer

The probability that at least one household owns a computer is 1 minus the probability that none of the households own a computer. The probability that a household does not own a computer is 1 - 0.565 = 0.435. For three households, the probability that none own a computer is 0.435^3. Therefore, the probability that at least one owns a computer is 1 - 0.435^3 = 0.918 or 91.8%.