3.8

x <- c(127,124,121,118,
       125,123,136,131,
       131,120,140,125,
       124,119,137,133,
       129,128,125,141,
       121,133,124,125,
       142,137,128,140,
       151,124,129,131,
       160,142,130,129,
       125,123,122,126)

mean(x)   # rata-rata sampel

## [1] 129.975

sd(x)     # standar deviasi sampel

## [1] 8.914084

hist(x,
     main = "Histogram Waktu Kegagalan Komponen",
     xlab = "Waktu Kegagalan (jam)",
     ylab = "Frekuensi",
     col = "lightblue",
     border = "black")

stem(x)

## 
##   The decimal point is 1 digit(s) to the right of the |
## 
##   11 | 89
##   12 | 0112334444
##   12 | 555556788999
##   13 | 011133
##   13 | 677
##   14 | 00122
##   14 | 
##   15 | 1
##   15 | 
##   16 | 0

median(x)

## [1] 128

quantile(x, probs = c(0.25, 0.5, 0.75), type = 6)

##    25%    50%    75% 
## 124.00 128.00 135.25