标题: 请教一道数学题目 [打印本页] 作者: normanever 时间: 2010-3-12 09:45 标题: 请教一道数学题目 请教各位这个题目应该选哪个？last month sold 15 houses, average price at 150000, while mean is 135000, which of following is ture?I. there must be at least one house sold more than 165000II. there must be at least one house sold more than 135000 and less than 150000;III. there must be at least one house sold less than 13500. 我举得只有第二个正确的，答案却选第一个选项。搞不懂。。跪求指导。。。