In a major city in the northwest United States, 28% of the days experience some period of rain.What is the probability that more than 12 days out of a random sample of 31 days will experience some period of rain?
A) 0.0918
B) 0.0806
C) 0.9082
D) 0.3871

Question

Quizplus · Accepted Answer

This is a binomial probability problem where n = 31 (number of trials), p = 0.28 (probability of success on a single trial), and we want the probability of having more than 12 successes (days with rain). The probability of more than 12 days of rain can be found by subtracting the probability of 12 or fewer days of rain from 1. Using a binomial probability calculator or tables, we find the cumulative probability for 12 or fewer days of rain and subtract from 1 to get the probability for more than 12 days of rain, which is approximately 0.0918.

In a Major City in the Northwest United States, 28