"Defense wins championships" is a common phrase used in the National Football League. Is defense associated with winning? The following data represent the winning percentage and the yards per game allowed during the 2014-2015 season for a random sample of teams.

(a) Test the belief that defense wins championships by determining whether a higher winning percentage is associated with a lower number of total yards given up at the α = 0.10 level of significance.
(b) Draw a scatter diagram to support your conclusion.