Question

1. Calculate the covariance and correlation coefficients by completing the below table, assuming sample data. Show all workings. (Note: You can calculate the mean and standard deviation of X & Y with Excel or your calculator; no working for their calculation is required.)

X	Y	(X - X bar)	(Y - Y bar)	(X - X bar)(Y - Y bar)
5	5
2	3
5	4
8	7
6	9

(b)       Comment on the direction and strength of the association between X and Y.

Answer 1

Here,

and

Since correlation coefficient of X and Y = 0.737391

So, we can conclude that there is a almost strong positive linear relationship between X and Y.