2.56 A corporation administers an aptitude test to all new sales representatives. Management is interested in the extent to which this test is able to predict weekly sales of new representatives. Aptitude test scores range from 0 to 30 with greater scores indicating a higher aptitude.

Weekly sales are recorded in hundreds of dollars for a random sample of 10 representatives. Test scores and weekly sales are as follows:

Test Score, x 12 30 15 24 14 18 28 26 19 27 Weekly Sales, y 20 60 27 50 21 30 61 54 32 57

a. Compute the covariance between test score and weekly sales.

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