In a poll conducted by a survey firm, 76% of respondents said that their jobs were sometimes or always stressful. Eight workers are chosen at random. What is the standard deviation of the Number of workers who find their jobs stressful?
A) 1.21
B) 0.43
C) 1.46
D) 2.47

Question

Quizplus · Accepted Answer

The standard deviation is the square root of the variance. The variance is the product of the probability of success, the probability of failure, and the number of trials. In this case, the probability of success is 0.76, the probability of failure is 0.24, and the number of trials is 8. So the variance is 0.76 * 0.24 * 8 = 1.46. The standard deviation is the square root of 1.46, which is 1.21.

In a Poll Conducted by a Survey Firm, 76% of Respondents