Hello all,

The probability distribution table is:-

Code:

Y
1 2 3
1 .1 .05 .02
X 2 .1 .35 .05
3 .03 .1 .2

Mean of x = 2.16 ; Mean of y = 2.04

Calculation of covariance is; ( ( 1 - 2.16 ) * ( 1 - 2.04 ) + ( 2 - 2.16 ) * ( 2 - 2.04 ) + ( 3 - 2.16 ) * ( 3 - 2.04 ) ) / 3 = 0.67

Even if we multiply probabilities; ( ( 1 - 2.16 ) * ( 1 - 2.04 ) * (.1) + ( 2 - 2.16 ) * ( 2 - 2.04 ) * (.35) + ( 3 - 2.16 ) * ( 3 - 2.04 ) * (.2) ) / 3 = 0.094

However COV(X,Y) in the answers is 0.23. Can someone show me how to correctly calculate covariance using the usual covariance formula.

Thanks