Question

How do you find a correlation coefficient?

Answer 1

do you have a problem?

Answer 2

ex. lets say youhave 8 numbers for x and 8 numbers for y

Note: Σ in the formula indicates summation of values. I'll go through the calculation in detail.

Your values for X and Y should come in pairs. First of all calculate Xbar and Ybar: these are the means of the X's and the Y's respectively, so for Xbar, add up your values for X and divide by 8. Similarly, for Ybar, add up your values for Y and divide by 8.

Next, we calculate Sx and Sy, the sample standard deviations of X and Y. To calcuate Sx, we proceed as follows:

for each X value, calcuate

(X - Xbar)^2

(the square of X - Xbar), add all these up and then divide by 7; taking the square root of your result yields Sx. The procedure for Sy is analagous.

Now we come to the final hurdle. For each pair of X and Y-values, calculate

(X - Xbar).(Y - Ybar)

(ie. multiply (X - Xbar) by (Y - Ybar)), then add up the results you get for all the pairs, and then divide by

7.Sx.Sy,

(ie. the product of Sx, Sy and (n-1) = 8 -1 = 7). This gives you the correlation coefficient.

Answer 3

so I find x and than I need the square root of what ever x- all the total of the xbar and than devide by 7?

Answer 4

correct

Answer 5

Thank you so much

Answer 6

now lets see if I can actually put this to use

Answer 7

haha right? i hate calculus

Answer 8

I hate math all together, defiantly my worse subject

Answer 9

so if x=3.45 and y-3.4 and the totals of the xbar was 13.8 and the total for the ybar was 13.6 how would I find the standard deviations

Answer 10

each side having 4 sets of numbers