A sports writer wished to see if a football filled with helium travels farther, on average, than a football filled with air. To test this, the writer used 18 adult male volunteers. These volunteers were randomly divided into two groups of nine men each. Group 1 kicked a football that was filled with helium to the recommended pressure. Group 2 kicked a football that was filled with air to the recommended pressure. The mean yardage for Group 1 was x1 = 300 yards with a standard deviation of s1 = 8 yards. The mean yardage for Group 2 was x2 = 296 yards with a standard deviation of s2 = 6 yards. Assume the two groups of kicks are independent. Let ] and M2 represent the mean yardage we would observe for the entire population represented by the volunteers if all members of this population kicked, respectively, a helium-filled football and an air-filled football. Assuming two-sample t procedures are safe to use and using Option 1 for the degrees of freedom, a 90% confidence interval for M1 - M2 is: O (-1.848, 9.8477). (-1.82, 9.8196). O (-3.112, 11.112). Incorrect