# Thread: Help finding coefficient correlations

1. ## Help finding coefficient correlations

Suppose that Y1 and Y2 have a coefficient correlation of p=.2
What is the coefficient correlation between

a. 1+2Y1 and 3+4Y2
b. 1+2Y1 and 3-4Y2
c. 1-2Y1 and 3-4Y2

2. ## Re: Help finding coefficient correlations

What definition of "correlation coefficient" (or "coefficient of correlation" but not "coefficient correlation") are you using?

3. ## Re: Help finding coefficient correlations

p=Cov(Y1,Y2)/(sigma1sigma2)

4. ## Re: Help finding coefficient correlations

Good. Now what is Cov(Y1, Y2) and what are sigma1 and sigma2 for each problem?

5. ## Re: Help finding coefficient correlations

That's the problem I'm having with the question, all the information in my first post is the information I was given. There were no parameters, variance or covariance given

6. ## Re: Help finding coefficient correlations

Hey sherloes.

Hint - Try expanding out the definition for the combination of random variables.

7. ## Re: Help finding coefficient correlations

Thanks, I'll try that