21-10NA 数学2 Q7

Mean of Data set X=5.50+5.5+5.60+5.65+5.665​​ =5.582> Mean of Data set Y=4.00+5.50+5.50​+5.60+5.65+5.666​ =5.318 ,方法2: Data set Y 由Data set X和4.00 组成, 加上Data set X 最小值还小的4.00后, Data set Y的mean 一定小于 Data set X的mean, 选A