The returns on ABC, XYZ stocks and on the market portfolio in four consecutive years are given in the following table.

Yr	ABC [return] %	XYZ [return] %	Market Return %
1	8	5	6
2	24	10	12
3	28	12	15
4	10	10	10

Find the BETA for ABC & XYZ.

Is there any correlation between ABC and XYZ ?

Kindly include the formulae used especially for covariance.