Table 6E.6 presents data on the ratings of quarterbacks for the 2008 National Football League season (source: The Sports Network). It is suspected that the rating (y) is related to the average number of yards gained per pass attempt (x). 

(a) Construct a scatter plot of quarterback rating versus yards per attempt. Comment on the suspicion that rating is related to yards per attempt.

(b) What is the simple correlation coefficient between these two variables?

Table 6E.6

Yards per Attempt Rating Points Player Team Philip Rivers SD 8.39 105.5 Chad Pennington MIA 7.67 97.4 Kurt Warner ARI 7.66 96.9 NO 7.98 Drew Brees 96.2 7.21 Peyton Manning IND 95 Rodgers GB 7.53 93.8 Aaron Schaub HOU Matt 8.01 92.7 Tony Romo DAL 7.66 91.4 Garcia Jeff TB 7.21 90.2 Matt NE 7.16 Cassel 89.4 Ryan 7.93 87.7 Matt ATL Shaun 7.10 87.5 Hill SF Seneca Wallace 6.33 87 SEA Manning NYG 6.76 Eli 86.4 Donovan McNabb PHI 6.86 86.4 Jay Cutler DEN 7.35 86 Trent Edwards BUF 7.22 85.4 Jake Delhomme 7.94 84.7 CAR 84.3 Jason Campbell WAS 6.41 6.77 81.7 David Garrard JAC Brett Favre NYJ 6.65 81 BAL Joe Flacco 80.3 6.94 Collins Kerry TEN 6.45 80.2 Roethlisberger PIT Ben 7.04 80.1 Kyle CHI 6.39 79.6 Orton JaMarcus Russell 6.58 77.1 OAK Tyler 6.21 Thigpen 76 Gus Freotte MIN 7.17 73.7 6.34 Dan Orlovsky DET 72.6 Marc Bulger STL 6.18 71.4 Ryan Fitzpatrick CIN 5.12 70 Derek CLE 5.71 66.5 Anderson