library(ggplot2)
library(dplyr)
## 
## Attaching package: 'dplyr'
## The following objects are masked from 'package:stats':
## 
##     filter, lag
## The following objects are masked from 'package:base':
## 
##     intersect, setdiff, setequal, union
data_mahasiswa <- read.csv("df_mahasiswa.csv")
head(data_mahasiswa)
##   X id_mahasiswa jenis_kelamin jam_belajar_per_hari frekuensi_login_lms
## 1 1       MHS001             L                    4                   1
## 2 2       MHS002             P                    4                   2
## 3 3       MHS003             P                    2                   6
## 4 4       MHS004             P                    5                   3
## 5 5       MHS005             L                    3                   2
## 6 6       MHS006             L                    3                   7
##   motivasi_belajar  ipk
## 1               82 3.12
## 2               73 3.45
## 3               71 3.07
## 4               98 3.43
## 5               81 2.83
## 6               61 3.10
str(data_mahasiswa)
## 'data.frame':    55 obs. of  7 variables:
##  $ X                   : int  1 2 3 4 5 6 7 8 9 10 ...
##  $ id_mahasiswa        : chr  "MHS001" "MHS002" "MHS003" "MHS004" ...
##  $ jenis_kelamin       : chr  "L" "P" "P" "P" ...
##  $ jam_belajar_per_hari: int  4 4 2 5 3 3 1 3 2 1 ...
##  $ frekuensi_login_lms : int  1 2 6 3 2 7 7 4 6 5 ...
##  $ motivasi_belajar    : int  82 73 71 98 81 61 44 69 44 46 ...
##  $ ipk                 : num  3.12 3.45 3.07 3.43 2.83 3.1 2.98 3.08 2.82 2.93 ...
colSums(is.na(data_mahasiswa))
##                    X         id_mahasiswa        jenis_kelamin 
##                    0                    0                    0 
## jam_belajar_per_hari  frekuensi_login_lms     motivasi_belajar 
##                    0                    0                    0 
##                  ipk 
##                    0
data_mahasiswa$jenis_kelamin
##  [1] "L" "P" "P" "P" "L" "L" "P" "L" "P" "L" "L" "P" "P" "L" "L" "L" "L" "L" "L"
## [20] "L" "L" "P" "L" "P" "L" "L" "L" "P" "L" "P" "P" "L" "P" "P" "L" "P" "L" "L"
## [39] "P" "L" "L" "P" "P" "P" "P" "L" "L" "L" "P" "P" "L" "L" "L" "L" "P"
table(data_mahasiswa$jenis_kelamin)
## 
##  L  P 
## 32 23
aggregate(ipk ~ jenis_kelamin, data = data_mahasiswa, mean)
##   jenis_kelamin      ipk
## 1             L 3.158125
## 2             P 3.176957
data_mahasiswa$id_mahasiswa[which.max(data_mahasiswa$motivasi_belajar)]
## [1] "MHS054"
dataf <- subset(data_mahasiswa, frekuensi_login_lms > 5)
dataf
##     X id_mahasiswa jenis_kelamin jam_belajar_per_hari frekuensi_login_lms
## 3   3       MHS003             P                    2                   6
## 6   6       MHS006             L                    3                   7
## 7   7       MHS007             P                    1                   7
## 9   9       MHS009             P                    2                   6
## 13 13       MHS013             P                    2                   6
## 17 17       MHS017             L                    2                   7
## 18 18       MHS018             L                    5                   7
## 21 21       MHS021             L                    1                   6
## 22 22       MHS022             P                    4                   7
## 26 26       MHS026             L                    4                   6
## 28 28       MHS028             P                    2                   6
## 31 31       MHS031             P                    2                   7
## 33 33       MHS033             P                    1                   7
## 37 37       MHS037             L                    4                   6
## 41 41       MHS041             L                    5                   7
## 42 42       MHS042             P                    4                   6
## 44 44       MHS044             P                    2                   7
## 51 51       MHS051             L                    4                   6
## 55 55       MHS055             P                    2                   7
##    motivasi_belajar  ipk
## 3                71 3.07
## 6                61 3.10
## 7                44 2.98
## 9                44 2.82
## 13               59 3.11
## 17               52 3.06
## 18               92 3.89
## 21               47 2.96
## 22               72 3.69
## 26               89 3.32
## 28               53 3.14
## 31               71 3.22
## 33               46 3.11
## 37               68 3.67
## 41               90 3.73
## 42               73 3.05
## 44               63 3.15
## 51               92 3.65
## 55               71 3.21
rata_belajar_4 <- mean(data_mahasiswa$ipk[data_mahasiswa$jam_belajar >= 4])
rata_belajar_kurang4 <- mean(data_mahasiswa$ipk[data_mahasiswa$jam_belajar < 4])

rata_belajar_4 > rata_belajar_kurang4
## [1] TRUE
mahasiswa_ipk_tinggi <- data_mahasiswa[which.max(data_mahasiswa$ipk), 
                                       c("id_mahasiswa", "ipk", "motivasi_belajar")]

mahasiswa_ipk_tinggi
##    id_mahasiswa  ipk motivasi_belajar
## 18       MHS018 3.89               92
mahasiswa_lolos <- subset(data_mahasiswa, ipk > 3.5 & motivasi_belajar > 85)
table(mahasiswa_lolos$jenis_kelamin)
## 
## L P 
## 4 1