三个样本率作比较，X<img border="0" alt="" src="https://img.weimei168.com/uploads/upimg/20230218/14002506_0.gif">＞X<img border="0" alt="" src="https://img.weimei168.com/uploads/upimg/20230218/14002506_0_1.gif"><img border="0" alt="" src="https://img.weimei168.com/uploads/upimg/20230218/14002506_0_2.gif">可认为