A production superintendent claims that there is no difference between the employee accident rates for the day versus the evening shifts in a large manufacturing plant. The number of accidents per day is recorded for both the day and evening shifts for n = 100 days. It is found that the number of accidents per day for the evening shift XE exceeded the corresponding number of accidents on the day shift xp on 63 of the 100 days. Do these results provide sufficient evidence to indicate that more accidents tend to occur on one shift than on the other or, equivalently, that P(xExD) 1/2?