correlation coefficient

correlation coefficient. how to get.

Square the x-x Bar column and the y-y Bar column. Add the X’s and divide by N. Same with Y, Add the Y’s and divide by N. Then do Square Root of the new X number in denominator and the new Y number in the denominator.

How to get Covariance

create matrix or x,y, X-X bar and y-Y Bar. Find the mean of X and then for Y. Once filled out, multiply X-X bar and Y-Y Bar in another column. Add this column and divide by N.

What do you do after you square the X-X Bar Column when finding the correlation coefficient?

Add the X’s and divide by N. Then Square root. Same for Y in denom.

For the Covariance what do you do after you multiply the X-X bar Column and the Y-Y bar column?

Add up figures and divide by N

How to get variance for a population? and then for a sample?

variance is simply taking the data point, subrtracing by mean of X or Y and divide by N or N-1 depening on sample vs population