Find the Mean and Variance of Random Variable Z = (5x+3)

[rogo0034]

Homework Statement

Find the Mean and Variance of Random Variable Z = (5x+3)

Using data set:

Using:

&

The Attempt at a Solution

 

[rogo0034]

Sorry the data set it so large, I've been trying to adjust it to no avail.EDIT: Fixed it, should be easier to view now

 

[Ray Vickson]

Homework Statement

Find the Mean and Variance of Random Variable Z = (5x+3)

Using data set:

Using:

&

The Attempt at a Solution

You have a very small table of x and f(x) values. What is stopping you from computing EX? Why don't you just compute EX, then use that value in the computation of Var(X) = sum f(x)*(x-EX)^2 ?

RGV

 

[rogo0034]

They want us to use the theorem and corollary, any ideas? I'm not too savvy with this stuff yet.

 

[Ray Vickson]

They want us to use the theorem and corollary, any ideas? I'm not too savvy with this stuff yet.

OK, so use the theorem and the corollary. Does the first theorem have E(X) in it? Do you know the value of E(X)? If not, you need to compute it. Does the second theorem have [itex] \text{Var}(X) = \sigma_x^2[/itex] in it? Do you know the value of Var(X)? If not, you need to compute it.

RGV