How do you calculate the covariance - I just don't understand how you get 42.800 out of this calculation:

Please help!!

Rest of the data here for reference:

Compute the covariance for X and Y. cov(X,Y)=n1i=1n(XiX)(YiY)=10i=111(Xi22)(Yi11) The covariance measures the strength of the linear relationship between two variables. The covariance is given by the following formula, where X is the sample mean for X,Y is the sample mean for Y,Xi is the ith value of X, Y is the ith value of Y, and n is the sample size. cov(X,Y)=n1i=1n(XiX)(YiY) Compute the sample mean for X X=22 (Round to six decimal places as needed.) Compute the sample mean for Y. Y=11 (Round to six decimal places as needed.) Compute the covariance for X and Y