数据70,71,72,73的方差是
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数据70,71,72,73的方差是
![数据70,71,72,73的方差是](/uploads/image/z/7215544-64-4.jpg?t=%E6%95%B0%E6%8D%AE70%2C71%2C72%2C73%E7%9A%84%E6%96%B9%E5%B7%AE%E6%98%AF)
70,71,72,73
先求平均数= (70+71+72+73)÷4=71.5
则方差=1/4[(70-71.5)²+(71-71.5)²+(72-71.5)²+(73-71.5)²]
=1/4[2.25+0.25+0.25+2.25]
=1/4(5.5)
=1.375
先求平均数= (70+71+72+73)÷4=71.5
则方差=1/4[(70-71.5)²+(71-71.5)²+(72-71.5)²+(73-71.5)²]
=1/4[2.25+0.25+0.25+2.25]
=1/4(5.5)
=1.375