Below is the probability distribution for random variable x.What is the standard deviation of this probability distribution?

A) 0.48
B) 0.69
C) 0.24
D) 2.00

Question

Below is the probability distribution for random variable x.What is the standard deviation of this probability distribution?

A) 0.48 
B) 0.69 
C) 0.24 
D) 2.00

Quizplus · Accepted Answer

To find the standard deviation, we first need to find the mean of the distribution.

Mean = (0.1*(-1) + 0.4*(0) + 0.3*(1) + 0.2*(2)) = 0.4

Next, we need to find the variance.

Variance = (0.1*(-1-0.4)^2 + 0.4*(0-0.4)^2 + 0.3*(1-0.4)^2 + 0.2*(2-0.4)^2) = 0.506

Finally, the standard deviation is the square root of the variance.

Standard deviation = sqrt(0.506) = 0.69

Therefore, the best choice is B.

Below Is the Probability Distribution for Random Variable X