KelasA.R

#buat data
x <- c(70,75,80,80,90)
x

## [1] 70 75 80 80 90

#melihat panjang/banyak data
length(x)

## [1] 5

#probabilitas data
table(x)/length(x)

## x
##  70  75  80  90 
## 0.2 0.2 0.4 0.2

#ratarata populasi
mean(x)

## [1] 79

#standar deviasi populasi
sd(x)*sqrt((length(x)-1)/length(x))

## [1] 6.63325

############
#data
x <- c(70,75,80,80,90)
x

## [1] 70 75 80 80 90

#Kombinasi data
sampel = combn(x,3);
sampel

##      [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10]
## [1,]   70   70   70   70   70   70   75   75   75    80
## [2,]   75   75   75   80   80   80   80   80   80    80
## [3,]   80   80   90   80   90   90   80   90   90    90

#rata-rata
ratarata = colMeans(sampel)
ratarata

##  [1] 75.00000 75.00000 78.33333 76.66667 80.00000 80.00000 78.33333 81.66667
##  [9] 81.66667 83.33333

#mengubah format data
ratarata = format(ratarata, digits = 4)
ratarata

##  [1] "75.00" "75.00" "78.33" "76.67" "80.00" "80.00" "78.33" "81.67" "81.67"
## [10] "83.33"

table(ratarata)

## ratarata
## 75.00 76.67 78.33 80.00 81.67 83.33 
##     2     1     2     2     2     1

prob = table(ratarata)/length(ratarata)
prob

## ratarata
## 75.00 76.67 78.33 80.00 81.67 83.33 
##   0.2   0.1   0.2   0.2   0.2   0.1

barplot(prob)

plot(prob)

ratarata

##  [1] "75.00" "75.00" "78.33" "76.67" "80.00" "80.00" "78.33" "81.67" "81.67"
## [10] "83.33"

ratarata <- as.numeric(ratarata)
mode(ratarata)

## [1] "numeric"

ratarata

##  [1] 75.00 75.00 78.33 76.67 80.00 80.00 78.33 81.67 81.67 83.33

#rata-rata distribusi sampling rata-rata sample
mean(ratarata)

## [1] 79

#standar deviasi distribusi sampling rata-rata sample
sd(ratarata)*sqrt((length(ratarata)-1)/length(ratarata))

## [1] 2.708014

#standar deviasi populasi
sd(x)*sqrt((length(x)-1)/length(x))

## [1] 6.63325