Question

Stuck on a probability problem

Answer 1

What is it?

Answer 2

Two standard normal variables Z1 and Z2 have covariance 0.3. Find the mean and variance of the random variable X=3Z1 - Z2

Answer 3

Damn haven't studied this yet.. I'm a newbie XD

Answer 4

@hartnn

Answer 5

Who is this hartnn guy.. I'm new to this website.

Answer 6

@ganeshie8

Answer 7

@dan815

Answer 8

Cov(X,Y) = E[XY] - E[X]*E[Y]
But I don't see how this helps.. Freaking hate probability

Answer 9

what does E stand for

Answer 10

Expected value, so for example if you have this scenario:
You get paid $1 if u get heads, but have to pay $2 if u get tails, your Expected winnings are:
E = 1*0.5+(-2)*0.5

Answer 11

oh so the mean is the expected value?

Answer 12

Pretty much