Point spreads of football games. During a football league season, oddsmakers establish a point spread on each game for betting purposes. For example, the defending champion were established as a 1-point underdog against another team in a season. The final scores of the games were compared against the final point spreads established by the betting agency. The difference between the outcome of the game and the point spread (called a point-spread error) was calculated for 12 games. The mean and standard deviation of the point-spread errors are x = -1.6 and s = 13.3. Suppose a researcher wants to know whether the true standard deviation of the point-spread errors exceeds 15. Conduct the analysis using a = .05.