Coefficient of determination and correlation.
Mary Sue wants to know if there is a connection between attendance at craft fairs and the number of exhibitors who have booths at the fair. For a casual sample of seven local craft fairs, she chose a random day of the fair and recorded the number of exhibitors. In data below, x represents the number of exhibitors and y represents the attendance in hundreds of people.
x

35

55

75

95

100

135

150

y

1.2

2.1

4.2

5.4

5.8

6.2

9.5

What does the coefficient of purpose tell you about variation in attendance and the variation in the number of exhibitors?