A sample of four 35-year-old males is asked about the average number of hours per week that he exercises, and is also given a blood cholesterol test. The data is recorded in the order pairs given below, in the form (Hours Exercising, Cholesterol Level):

(2.6,228),(3.7,198),(5,188),(6.9,195)(2.6,228),(3.7,198),(5,188),(6.9,195)

Find the coefficient of correlation for this sample.