Who are you going to use for the upcoming game (basketball)?

a <- c(7,8,9,9,10,10,11,11,12,13)
b <- c(7,8,8,10,10,10,10,11,11,13)
c <- c(3,3,6,7,7,10,10,10,11,13,30)
c <- c(3,3,6,7,7,10,11,13,15,20,30)

data <- list(a,b,c)
data
sapply(data,mean)
sapply(data,sd)
sapply(data,var)

> data
[[1]]
 [1]  7  8  9  9 10 10 11 11 12 13

[[2]]
 [1]  7  8  8 10 10 10 10 11 11 13

[[3]]
 [1]  3  3  6  7  7 10 10 10 11 13 30

> sapply(data,mean)
[1] 10.0  9.8 10.0
> sapply(data,sd)
[1] 1.825742 1.751190 7.362065
> sapply(data,var)
[1]  3.333333  3.066667 54.200000

range

quartile
variance

• $ \sum \text{deviation score}^2 = \sum \text{ds}^2 $

• $ \sum \text{error}^2 $
  • error = 평균값으로 개인값을 추측했을 때 발생하는 오차
  • (평균으로 추측했을 때 생기는) 오차의 제곱의 합
  • (오차의) 제곱의 합
  • 제곱의 합
  • Sum of Square (SS)

• $ \sum \text{ds}^2 = \text{SS} = \text{Sum of Square} $ ¹⁾

• $$ \text{variance} = \frac {SS}{n-1} = \frac {SS}{df}$$
• calculation of variance (an easy way)
  • $ \displaystyle \frac{\sum(X_{i})}{N} - \mu^2$

standard deviation
standard score