options(repos = c(CRAN = "https://cloud.r-project.org"))

library(ggplot2)
## Warning: package 'ggplot2' was built under R version 4.4.3
library(rmarkdown)
## Warning: package 'rmarkdown' was built under R version 4.4.3
install.packages("xfun")
## package 'xfun' successfully unpacked and MD5 sums checked
## Warning: cannot remove prior installation of package 'xfun'
## Warning in file.copy(savedcopy, lib, recursive = TRUE): problem copying
## C:\Program Files\R\R-4.4.1\library\00LOCK\xfun\libs\x64\xfun.dll to C:\Program
## Files\R\R-4.4.1\library\xfun\libs\x64\xfun.dll: Permission denied
## Warning: restored 'xfun'
## 
## The downloaded binary packages are in
##  C:\Users\ASUS\AppData\Local\Temp\Rtmp0m47aS\downloaded_packages
# install.packages("agricolae")
install.packages(c("knitr", "rmarkdown", "ggplot2", "agricolae", "tidyverse"))
## Warning: packages 'rmarkdown', 'ggplot2' are in use and will not be installed
## package 'knitr' successfully unpacked and MD5 sums checked
## package 'agricolae' successfully unpacked and MD5 sums checked
## package 'tidyverse' successfully unpacked and MD5 sums checked
## 
## The downloaded binary packages are in
##  C:\Users\ASUS\AppData\Local\Temp\Rtmp0m47aS\downloaded_packages

Jawaban No. 1

# Install & load package
install.packages("agricolae")  
## package 'agricolae' successfully unpacked and MD5 sums checked
## 
## The downloaded binary packages are in
##  C:\Users\ASUS\AppData\Local\Temp\Rtmp0m47aS\downloaded_packages
library(agricolae)
## Warning: package 'agricolae' was built under R version 4.4.3
# Buat data sesuai dengan format incomplete block design
data <- data.frame(
  blok = rep(c("A", "B", "C", "D"), each = 4),
  logam = rep(1:4, times = 4),
  nilai = c(80, 83, NA, 86,   # A
            NA, 75, 78, 84,    # B
            86, 88, 90, NA,    # C
            92, NA, 94, 80)    # D
)

data$blok <- factor(data$blok)
data$logam <- factor(data$logam)
# Membentuk desain blok tidak lengkap dengan data yang tersedia
library(agricolae)
model <- with(data, design.bib(trt = logam, k = 3, r = NULL, seed = 123))
## 
## Parameters BIB
## ==============
## Lambda     : 8
## treatmeans : 16
## Block size : 3
## Blocks     : 80
## Replication: 60 
## 
## Efficiency factor 0.7111111 
## 
## <<< Book >>>
model
## $parameters
## $parameters$design
## [1] "bib"
## 
## $parameters$trt
##  [1] 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4
## Levels: 1 2 3 4
## 
## $parameters$k
## [1] 3
## 
## $parameters$serie
## [1] 2
## 
## $parameters$seed
## [1] 123
## 
## $parameters$kinds
## [1] "Super-Duper"
## 
## 
## $statistics
##        lambda treatmeans blockSize blocks  r Efficiency
## values      8         16         3     80 60  0.7111111
## 
## $sketch
##       [,1] [,2] [,3]
##  [1,] "1"  "4"  "3" 
##  [2,] "1"  "2"  "1" 
##  [3,] "3"  "1"  "1" 
##  [4,] "1"  "3"  "2" 
##  [5,] "1"  "1"  "1" 
##  [6,] "1"  "2"  "3" 
##  [7,] "1"  "2"  "2" 
##  [8,] "1"  "3"  "4" 
##  [9,] "1"  "2"  "3" 
## [10,] "4"  "1"  "2" 
## [11,] "4"  "1"  "3" 
## [12,] "4"  "1"  "4" 
## [13,] "2"  "3"  "1" 
## [14,] "4"  "1"  "1" 
## [15,] "2"  "1"  "3" 
## [16,] "2"  "3"  "3" 
## [17,] "3"  "4"  "3" 
## [18,] "3"  "4"  "3" 
## [19,] "1"  "4"  "4" 
## [20,] "4"  "2"  "4" 
## [21,] "3"  "1"  "2" 
## [22,] "2"  "2"  "3" 
## [23,] "3"  "4"  "1" 
## [24,] "2"  "4"  "4" 
## [25,] "1"  "2"  "2" 
## [26,] "2"  "2"  "4" 
## [27,] "2"  "2"  "1" 
## [28,] "4"  "4"  "3" 
## [29,] "4"  "4"  "1" 
## [30,] "3"  "4"  "1" 
## [31,] "4"  "4"  "1" 
## [32,] "1"  "4"  "3" 
## [33,] "1"  "1"  "2" 
## [34,] "2"  "2"  "4" 
## [35,] "4"  "3"  "2" 
## [36,] "4"  "1"  "2" 
## [37,] "1"  "4"  "4" 
## [38,] "3"  "1"  "4" 
## [39,] "4"  "2"  "3" 
## [40,] "3"  "3"  "1" 
## [41,] "3"  "1"  "4" 
## [42,] "2"  "1"  "3" 
## [43,] "2"  "2"  "4" 
## [44,] "4"  "2"  "2" 
## [45,] "2"  "3"  "1" 
## [46,] "2"  "3"  "3" 
## [47,] "2"  "1"  "4" 
## [48,] "2"  "4"  "3" 
## [49,] "3"  "2"  "4" 
## [50,] "3"  "2"  "1" 
## [51,] "4"  "2"  "3" 
## [52,] "3"  "3"  "4" 
## [53,] "3"  "2"  "1" 
## [54,] "1"  "3"  "3" 
## [55,] "2"  "1"  "2" 
## [56,] "1"  "1"  "4" 
## [57,] "3"  "1"  "4" 
## [58,] "3"  "2"  "2" 
## [59,] "1"  "3"  "3" 
## [60,] "3"  "1"  "2" 
## [61,] "1"  "1"  "4" 
## [62,] "4"  "4"  "3" 
## [63,] "2"  "2"  "1" 
## [64,] "3"  "2"  "3" 
## [65,] "3"  "4"  "2" 
## [66,] "4"  "4"  "3" 
## [67,] "4"  "4"  "2" 
## [68,] "4"  "3"  "2" 
## [69,] "1"  "3"  "1" 
## [70,] "4"  "3"  "3" 
## [71,] "2"  "2"  "4" 
## [72,] "3"  "2"  "3" 
## [73,] "4"  "2"  "1" 
## [74,] "1"  "1"  "2" 
## [75,] "2"  "4"  "4" 
## [76,] "2"  "4"  "3" 
## [77,] "2"  "4"  "1" 
## [78,] "3"  "3"  "1" 
## [79,] "4"  "1"  "1" 
## [80,] "4"  "3"  "2" 
## 
## $book
##     plots block logam
## 1     101     1     1
## 2     102     1     4
## 3     103     1     3
## 4     201     2     1
## 5     202     2     2
## 6     203     2     1
## 7     301     3     3
## 8     302     3     1
## 9     303     3     1
## 10    401     4     1
## 11    402     4     3
## 12    403     4     2
## 13    501     5     1
## 14    502     5     1
## 15    503     5     1
## 16    601     6     1
## 17    602     6     2
## 18    603     6     3
## 19    701     7     1
## 20    702     7     2
## 21    703     7     2
## 22    801     8     1
## 23    802     8     3
## 24    803     8     4
## 25    901     9     1
## 26    902     9     2
## 27    903     9     3
## 28   1001    10     4
## 29   1002    10     1
## 30   1003    10     2
## 31   1101    11     4
## 32   1102    11     1
## 33   1103    11     3
## 34   1201    12     4
## 35   1202    12     1
## 36   1203    12     4
## 37   1301    13     2
## 38   1302    13     3
## 39   1303    13     1
## 40   1401    14     4
## 41   1402    14     1
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## 43   1501    15     2
## 44   1502    15     1
## 45   1503    15     3
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## 60   2003    20     4
## 61   2101    21     3
## 62   2102    21     1
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## 65   2202    22     2
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## 83   2802    28     4
## 84   2803    28     3
## 85   2901    29     4
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## 87   2903    29     1
## 88   3001    30     3
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## 180  6003    60     2
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## 234  7803    78     1
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## 238  8001    80     4
## 239  8002    80     3
## 240  8003    80     2
# Hilangkan data yang NA dulu
data.clean <- na.omit(data)

# Lakukan analisis ANOVA
anova_model <- aov(nilai ~ blok + logam, data = data.clean)
summary(anova_model)
##             Df Sum Sq Mean Sq F value Pr(>F)
## blok         3 186.00   62.00   1.932  0.243
## logam        3  22.25    7.42   0.231  0.871
## Residuals    5 160.42   32.08

Interpretasi: * Analisis RABTL pada data tekanan dan logam menunjukkan bahwa:

Dengan demikian, dapat disimpulkan bahwa tidak ada pengaruh nyata dari jenis logam maupun tekanan terhadap nilai uji, berdasarkan analisis dengan RABTL.

Jawaban No. 2

# Data pengamatan hasil uji pembakaran
nilai <- c(21, 22, 17, 23, 29,
           27, 24, 32, 27, 33,
           28, 38, 26, 29, 21,
           26, 31, 26, 23, 22,
           29, 32, 28, 28, 32)

# Baris = bahan mentah (row), Kolom = operator (col), Perlakuan = A–E
row <- factor(rep(1:5, each=5))
col <- factor(rep(1:5, times=5))
trt <- factor(c("A", "B", "C", "D", "E",
                "B", "C", "D", "E", "A",
                "C", "D", "E", "A", "B",
                "D", "E", "A", "B", "C",
                "E", "A", "B", "C", "D"))

# Data frame lengkap
data <- data.frame(row, col, trt, nilai)
# Analisis dengan aov
model <- aov(nilai ~ row + col + trt, data=data)
summary(model)
##             Df Sum Sq Mean Sq F value Pr(>F)  
## row          4 177.36   44.34   3.593 0.0379 *
## col          4  44.96   11.24   0.911 0.4885  
## trt          4 158.56   39.64   3.212 0.0520 .
## Residuals   12 148.08   12.34                 
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Interpretasi:

p-value = 0.0379 → signifikan (karena < 0.05).

Artinya, bahan mentah yang digunakan berpengaruh signifikan terhadap hasil pembakaran.

p-value = 0.4885 → tidak signifikan.

Artinya, perbedaan antar operator tidak memberikan pengaruh signifikan terhadap hasil.

p-value = 0.0520 → mendekati signifikan, masuk kategori “marginally significant” (ada tanda titik “.”).

Artinya, jenis bahan bakar memiliki pengaruh yang hampir signifikan terhadap hasil pembakaran, tetapi belum cukup kuat secara statistik pada taraf 5%.

Kesimpulan:

Jawaban No. 3

# Data observasi (tingkat kecelakaan)
nilai <- c(22, 20, 15, 5,     # baris 1
           21, 15, 8, 37,     # baris 2
           30, 9, 56, 35,     # baris 3
           7, 52, 40, 25)     # baris 4

# Baris = jenis kapal, Kolom = operator, Perlakuan = jenis kapal (A-D)
row <- factor(rep(1:4, each=4))
col <- factor(rep(1:4, times=4))
trt <- factor(c("A", "B", "C", "D",
                "B", "C", "D", "A",
                "C", "D", "A", "B",
                "D", "A", "B", "C"))

data3 <- data.frame(row, col, trt, nilai)
# Model ANOVA Persegi Latin
model3 <- aov(nilai ~ row + col + trt, data = data3)
summary(model3)
##             Df Sum Sq Mean Sq F value   Pr(>F)    
## row          3  819.7   273.2   8.820 0.012820 *  
## col          3  194.7    64.9   2.095 0.202355    
## trt          3 2502.2   834.1  26.923 0.000704 ***
## Residuals    6  185.9    31.0                     
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Interpretasi:

F value = 26.923, p-value = 0.000704 (< 0.001) → sangat signifikan

Artinya, jenis kapal memiliki pengaruh sangat signifikan terhadap tingkat kecelakaan.

p-value = 0.01282 (< 0.05) → signifikan

Artinya, jenis kapal sebagai blok juga memberikan pengaruh terhadap hasil, bisa jadi karena perbedaan struktur atau kondisi kapal.

p-value = 0.20236 (> 0.05) → tidak signifikan

Artinya, perbedaan antar operator tidak memberikan pengaruh signifikan terhadap hasil kecelakaan.

Kesimpulan:

Dengan demikian, pengambilan keputusan untuk pengurangan kecelakaan laut harus difokuskan pada jenis kapal yang digunakan, bukan pada siapa operatornya.

Jawaban No. 4

Berdasarkan struktur data yang diberikan — yaitu perlakuan lama vernalisasi (hari) dan blok konsentrasi GA3 (ppm), namun tidak semua kombinasi tersedia (missing) — maka model perancangan yang paling tepat digunakan adalah: Rancangan Blok Random Tak Lengkap Seimbang (RBRTLS)

Alasan:

Hal ini karena tidak semua kombinasi perlakuan dan blok tersedia, dan perlakuan utama (lama vernalisasi) hanya dapat diuji pada sebagian blok. Desain ini mencerminkan keterbatasan jumlah perlakuan yang bisa diterapkan di setiap blok secara acak, sesuai prinsip RBRTLS.

Analisis:

# Input data RBRTLS (dalam format long)
vernal <- c(0, 0, NA, 0, 
            14, NA, 33, 45, 
            NA, 39, 39, 36,
            31, 42, 44, NA)

# Faktor perlakuan: lama vernalisasi
perlakuan <- factor(c(0, 0, NA, 0,
                      14, NA, 14, 14,
                      NA, 28, 28, 28,
                      42, 42, 42, NA))

# Faktor blok: konsentrasi GA3
blok <- factor(rep(c("GA3_0", "GA3_500", "GA3_1000", "GA3_1500"), each = 4))

# Buat dataframe (hapus NA untuk analisis)
data <- data.frame(vernal, perlakuan, blok)
data_clean <- na.omit(data)  # hanya ambil baris lengkap
# Gunakan model linear untuk RBRTLS
model_rb <- lm(vernal ~ perlakuan + blok, data = data_clean)

# Tampilkan hasil ANOVA
anova(model_rb)
## Analysis of Variance Table
## 
## Response: vernal
##           Df  Sum Sq Mean Sq F value   Pr(>F)   
## perlakuan  3 3022.25 1007.42  13.598 0.001657 **
## Residuals  8  592.67   74.08                    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Interpretasi:

Faktor perlakuan (lama vernalisasi) memiliki nilai F = 13.598 dan p-value = 0.001657, yang berarti:

Berdasarkan analisis dengan model RBRTLS, lama vernalisasi berpengaruh sangat signifikan terhadap umur tanaman mulai berbunga (p = 0.0017). Dengan demikian, pengaturan waktu vernalisasi sangat penting dalam memengaruhi percepatan fase berbunga tanaman, bahkan lebih dominan dibanding pengaruh blok (GA3) yang dibatasi jumlahnya.

Kesimpulan: