There is recent speculation that the Super Bowl games, which determine the NFL champion, are becoming more competitive over time. The competitiveness of the game draws much attention from the gambling industry, which is affected by the winning margin, or point spread, of the outcome. To investigate this theory, I’ve constructed the Excel file Super Bowl scores.xlsx,which provides the winning and losing scores for each Super Bowl from 1986 to 2018.

a. Using these data and a significance level equal to 0.05, determine if the point spread of the game has changed significantly.

b. Provide a forecast for the point spread for the 2019 Super Bowl.

c. What are the limitations of your forecasting model?