Question

Compute the mean and variance of the following probability distribution. (Round your answers to 2 decimal places.) х 4 Px) .10 25 10 13 .30 .35 Click here for the Excel Data File Mean Variance

Answer 1

solution:

first of all make the necessary computation of the given probability distribution as shown in the below table:

X X*P(x) 0.4 X^2 16 4 P(x) 0.10 0.25 0.30 0.35 (X^2)*P(x) 1.6 12.25 7 1.75 49 10 3 100 30 13 4.55 59.15 169 334 total 9.7 103

mean = $\mu= \sum (X*P(X)) = 9.7$

variance =

$\sigma^2= \sum (X^2*P(X)) -\mu^2 = 103-9.7^2 = 8.91$