Table below shows Discrete Probability Distribution of Rand

. Table below shows Discrete Probability Distribution of Random Variable.
Use these data to calculate Expected Value of x and Standard Deviation.

x

2

4

5

6

9

P(x)

0.1

0.2

0.4

0.2

0.1

Solution

Consider the table:

Thus,

E(x) = 5.1 [answer, expected value]

s(x) = sqrt(E(x^2) - E(x)^2) = sqrt(28.9-5.1^2) = 1.7 [answer, standard deviation]