题目内容
收藏
纠错
题目材料:
In a survey, 100 travel agents each ranked Airlines A,B and C in order of preference. Each of the 100 travel agents also rated the three airlines in five categories on a scale of 1 through 10, with 10 being the best rating.
If each of the average ratings was the arithmetic mean of the ratings given by the 100 travel agents, approximately how much greater was the total of the ratings given to all three airlines for reliability than that for promptness?
D显示答案