2.56 Management of a local retail outlet in Australia wants to predict weekly online shopping sales. It administers an aptitude test to all sales people, where test scores range from 0 to 10 with greater scores indicating a higher aptitude. Test scores and weekly sales (in AU$000) are as follows:

Test Score (x) 10 9 8 8 7 9 6 5 9 7 Weekly Sales (y) 23 61 17 30 21 20 51 44 31 17

a. Compute the covariance.

b. Compute the correlation between test score and weekly sales.