变量 90.4,80.43,100.54,91.32,102.23,109.43,101.32,82.43,79.33,92.3

解答

变量

90.4, 80.43, 100.54, 91.32, 102.23, 109.43, 101.32, 82.43, 79.33, 92.3

105.31951 \dots

求解步骤

计算平均值，

\overset{x}{ˉ} : 92.973

计算

i = 1 \sum n (x_{i} - \overset{x}{ˉ})^{2} : 947.87561

计算数据集中的项的数量:

n = 10

计算

Va r (X) = i = 1 \sum n \frac{( x _{i} - x ˉ ) ^{2}}{n - 1} : 105.31951 \dots

105.31951 \dots

C (6, 2)

s t d 100, 140, 130, 180, 80, 160

s t d 10.5, 3.3, 5.3

19 C 2

a r i t hm e t i c m e an 10, 9, 8, 7, 8, 6, 10, 6