Question

初中数学题方差计算

一组数 92 93 94 99 94.5 93的方差是多少？请附计算过程啊？

Answer 1

首先计算平均数：(92 +93+ 94 +99+ 94.5 +93)/6=94.25
方差=[(92-94.25)^2+(93-94.25)^2+(94-94.25)^2+(99-94.25)^2+(94.5-94.25)^2+(93-94.25)^2]/6=5.146

Answer 2

（1）求出平均数：(92 +93+ 94 +99+ 94.5 +93)/6=94.25
（2）根据方差求法：方差=[(92-94.25)^2+(93-94.25)^2+(94-94.25)^2+(99-94.25)^2+(94.5-94.25)^2+(93-94.25)^2]/6=5.146

Answer 3

解：由题意得 (92 +93+ 94 +99+ 94.5 +93)/6=94.25
S=[(92-94.25)^2+(93-94.25)^2+(94-94.25)^2+(99-94.25)^2+(94.5-94.25)^2+(93-94.25)^2]/6=5.146

Answer 4

92 +93+ 94 +99+ 94.5 +93)/6=94.25
方差=[(92-94.25)^2+(93-94.25)^2+(94-94.25)^2+(99-94.25)^2+(94.5-94.25)^2+(93-94.25)^2]/6=5.146