A major oil company is studying the relationship between the daily traffic count and the number of gallons of gasoline pumped at company stations. A sample of eight company owned stations is selected and the following information obtained:
Location Total Gallons of Gas Pumped (000) Traffic Count of Vehicles (000)
West St. 120 4
Willouhby St. 180 6
Mallard Rd. 140 5
Pheasant Rd. 150 5
I-75 210 8
Kinzua Rd. 100 3
Front St. 90 3
Indiana Ave. 80 2
a. Compute the coefficient of correlation
b. Compute the coefficient of determination.
c. Interpret the meaning of the coefficient of determination.
d. Compare the calculated t value to the Student's t -value found in the Appendix to evaluate a null hypothesis that the correlation in the population is zero, versus the alternate hypothesis that the correlation is greater than zero. Use the 0.05 significance level.