求方差,概率
问题描述:
求方差,概率
甲:182,170,171,179,179,162,163,168,168,158.乙:181,170,173,176,178,179,162,165,168,159.(1)甲的样本方差.(2)从乙中随机抽取两个不低于173求176被抽中的概率
答
(1)甲平均数:(182+170+171+179+179+162+163+168+168+158)/10=170
S²:(182-170)²+(170-170)²+.+(168-170)²+(158-170)²/10=57.2
(2)没太看懂你的问题