## anonymous 5 years ago how to find correlation coeff in statistics???

1. anonymous

Do you know the definition and can't use it, or is it the case you don't even have the definition?

2. anonymous

The population correlation coefficient is defined as$\rho_{X,Y}=\frac{cov(X,Y)}{\sigma_X \sigma_y}=\frac{E[(X-\mu_X)(Y-\mu_Y)]}{\sigma_X \sigma_Y}$

3. anonymous

The sample correlation coefficient is$r=\frac{\sum_{i=1}^{n}(X_i-m_X)(Y_i-m_Y)}{\sqrt{\sum_{i=1}^{n}(X_i-m_X)^2}\sqrt{\sum_{i=1}^{n}(Y_i-m_Y)^2}}$where $m_X,m_Y$are the *sample* means, and $X_i,Y_i$are your paired data points.

4. anonymous

5. anonymous

He's using a different formula at the end, though it's actually derived from what I gave you above. Follow his method for your own data.

6. anonymous

I'm kind of busy right now, so I'm not able to go into it in much more detail at the moment, but if you need more help, let me know. It's not a hard thing to do (calculate the coefficient), just a pain to do online in this forum.