Question

The following is the distribution of a random variable X.

X=0, 1, 2, 3
P(X)=0.1, 0.3, 0.4, 0.2
Find E(X)​

Answer 1

`E(X)= 0*0.1 +1*0.3 +2*0.4 +3*0.2`

And adding the values we got:

`E(X) =0 +0.3 +0.8 +0.6 = 1.7`

So then the expected value for this random variable would be
`E(X) =1.7`

Explanation:

For this case we have the following probability distribution given:

X 0 1 2 3

P(X) 0.1 0.3 0.4 0.2

And for this case the expected value with the following formula:

`E(X) =\sum_(i=1)^n X_i P(X_i)`

And replacing we have:

`E(X)= 0*0.1 +1*0.3 +2*0.4 +3*0.2`

And adding the values we got:

`E(X) =0 +0.3 +0.8 +0.6 = 1.7`

So then the expected value for this random variable would be
`E(X) =1.7`