标准差的平方s²,称为方差
平均数=(9.9+10.3+10+10.1+9.7)/5=10
方差=[(9.9-10)²+(10.3-10)²+(10-10)²+(10.1-10)²+(9.7-10)²]/5
=[0.01+0.09+0+0.01+0.09]/5
=0.04
标准差的平方s²,称为方差
平均数=(9.9+10.3+10+10.1+9.7)/5=10
方差=[(9.9-10)²+(10.3-10)²+(10-10)²+(10.1-10)²+(9.7-10)²]/5
=[0.01+0.09+0+0.01+0.09]/5
=0.04