A company is interviewing applicants for managerial positions.They plan to hire two people.They have already rejected most candidates and are left with a group of 7 applicants of whom 6 are women.Unable to differentiate further between the applicants,they choose two people at random from this group of 7.Let the random variable X be the number of men that are chosen.Find the standard deviation of X.
A)σ = 0.49
B)σ = 0.42
C)σ = 0.45
D)σ = 0.20
E)σ = 0.55

Question

Quizplus · Accepted Answer

The random variable X can take values 0 or 1. The probability of choosing 0 men (2 women) is 15/21, and the probability of choosing 1 man is 6/21. The variance is calculated as Var(X) = E(X^2) - [E(X)]^2, and the standard deviation is the square root of the variance, which is approximately 0.45.

A Company Is Interviewing Applicants for Managerial Positions