# Math Help - covariance

1. ## covariance

I dont understand how it comes to this?

2. ## Re: covariance

Hi Helpmeplease1!

Do you have the formulas for covariance and correlation?
Those need to be applied.

For reference:
Covariance - Wikipedia, the free encyclopedia
Correlation and dependence - Wikipedia, the free encyclopedia

However, you still should define $w_a$ and $w_b$.
What are they?