In exercise 24, an estimated regression equation was developed relating the percentage of games won by a team in the National Football League for the 2011 season (y) given the average number of passing yards obtained per game on offense (x1) and the average number of yards given up per game on defense (x2) (ESPN website, November 3, 2012). The estimated regression equation was
y = 60.5 + .319x1 – .241x2
a. Predict the percentage of games won for a particular team that averages 225 passing yards per game on offense and gives up an average of 300 yards per game on defense.
b. Develop a 95% confidence interval for the mean percentage of games won for all teams that average 225 passing yards per game on offense and gives up an average of 300 yards per game on defense.