library(tidyverse)
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#Membangkitkan data

##skenario

Y : Pertumbuhan jumlah Penjualan di Toko HABIBI di tahun 2023

X1 : pengunjung toko (perhari dalam setahun)

X2 : kualitas pelayanan toko (ratig 1- 4)

#Jumlah hari dalam setahun

hari <- 365

#Membangkitkan data pengunjung toko (X1) X1 : data pengunjung toko

set.seed(123)
X1 <- round(rnorm(hari, 70, 15))
X1
##   [1]  62  67  93  71  72  96  77  51  60  63  88  75  76  72  62  97  77  41
##  [19]  81  63  54  67  55  59  61  45  83  72  53  89  76  66  83  83  82  80
##  [37]  78  69  65  64  60  67  51 103  88  53  64  63  82  69  74  70  69  91
##  [55]  67  93  47  79  72  73  76  62  65  55  54  75  77  71  84 101  63  35
##  [73]  85  59  60  85  66  52  73  68  70  76  64  80  67  75  86  77  65  87
##  [91]  85  78  74  61  90  61 103  93  66  55  59  74  66  65  56  69  58  45
## [109]  64  84  61  79  46  69  78  75  72  60  57  55  72  56  63  66  98  60
## [127]  74  71  56  69  92  77  71  64  39  87  48  81  99  48  81  66  46  47
## [145]  46  62  48  80 102  51  82  82  75  55  68  66  78  64  85  64  86  54
## [163]  51 119  64  74  80  63  78  76  67  71  69 102  59  54  71  75  77  63
## [181]  54  89  65  57  66  67  87  71  81  63  73  65  71  57  50 100  79  51
## [199]  61  52 103  90  66  78  64  63  58  61  95  69  72  74  88  62  55  95
## [217]  63  59  51  51  61  79  87  81  65  71  59  59  83  55  99  69  73  59
## [235]  61  50  67  76  75  58  58  62  92  53  67  99  68  50  60  77  64  62
## [253]  65  71  94  69  86  79  68  47  62  63  71  90 104  93  68  44  64  71
## [271]  83  84  80  49  83  63  73  71  76  70  45  81  76  66  72  72  73  95
## [289]  67  73  88  86  87  61 100  71  98  50  70  89  59  59  56  54  63  75
## [307]  40  73  89 101  90  81  44  61  65  81  68  51  95  84  74  88  50  80
## [325]  62  80  69  79  90  70  85  52  59  93  76  39  50  67  83  68  79  84
## [343]  95  71  69  44  71  61  55  67  85  40  64  72  57  75  76  70  33 109
## [361]  67  80  74  85  82

#Membangkitkan data rate kualitas pelayanan toko (X2)

set.seed(123)
X2 <- round(rnorm(hari, 4, 0.5),2)
X2
##   [1] 3.72 3.88 4.78 4.04 4.06 4.86 4.23 3.37 3.66 3.78 4.61 4.18 4.20 4.06 3.72
##  [16] 4.89 4.25 3.02 4.35 3.76 3.47 3.89 3.49 3.64 3.69 3.16 4.42 4.08 3.43 4.63
##  [31] 4.21 3.85 4.45 4.44 4.41 4.34 4.28 3.97 3.85 3.81 3.65 3.90 3.37 5.08 4.60
##  [46] 3.44 3.80 3.77 4.39 3.96 4.13 3.99 3.98 4.68 3.89 4.76 3.23 4.29 4.06 4.11
##  [61] 4.19 3.75 3.83 3.49 3.46 4.15 4.22 4.03 4.46 5.03 3.75 2.85 4.50 3.65 3.66
##  [76] 4.51 3.86 3.39 4.09 3.93 4.00 4.19 3.81 4.32 3.89 4.17 4.55 4.22 3.84 4.57
##  [91] 4.50 4.27 4.12 3.69 4.68 3.70 5.09 4.77 3.88 3.49 3.64 4.13 3.88 3.83 3.52
## [106] 3.98 3.61 3.17 3.81 4.46 3.71 4.30 3.19 3.97 4.26 4.15 4.05 3.68 3.58 3.49
## [121] 4.06 3.53 3.75 3.87 4.92 3.67 4.12 4.04 3.52 3.96 4.72 4.23 4.02 3.79 2.97
## [136] 4.57 3.27 4.37 4.95 3.28 4.35 3.87 3.21 3.24 3.20 3.73 3.27 4.34 5.05 3.36
## [151] 4.39 4.38 4.17 3.50 3.94 3.86 4.28 3.81 4.49 3.81 4.53 3.48 3.37 5.62 3.79
## [166] 4.15 4.32 3.76 4.26 4.18 3.89 4.03 3.98 5.06 3.63 3.45 4.02 4.16 4.22 3.77
## [181] 3.47 4.63 3.83 3.57 3.88 3.90 4.55 4.04 4.38 3.75 4.11 3.84 4.05 3.55 3.34
## [196] 5.00 4.30 3.37 3.69 3.41 5.10 4.66 3.87 4.27 3.79 3.76 3.61 3.70 4.83 3.97
## [211] 4.06 4.12 4.62 3.74 3.50 4.84 3.78 3.64 3.38 3.36 3.71 4.31 4.55 4.35 3.82
## [226] 4.03 3.65 3.64 4.44 3.49 4.98 3.95 4.11 3.63 3.71 3.34 3.91 4.21 4.16 3.61
## [241] 3.61 3.75 4.75 3.43 3.91 4.95 3.95 3.32 3.67 4.24 3.81 3.72 3.83 4.05 4.80
## [256] 3.96 4.54 4.32 3.94 3.23 3.74 3.76 4.02 4.65 5.15 4.77 3.93 3.12 3.81 4.04
## [271] 4.42 4.48 4.34 3.30 4.42 3.78 4.09 4.04 4.21 4.01 3.17 4.37 4.19 3.87 4.06
## [286] 4.07 4.11 4.82 3.89 4.08 4.58 4.53 4.57 3.71 5.00 4.03 4.93 3.32 4.01 4.62
## [301] 3.64 3.62 3.53 3.47 3.78 4.17 2.99 4.11 4.62 5.02 4.65 4.38 3.14 3.70 3.82
## [316] 4.35 3.95 3.37 4.84 4.46 4.12 4.61 3.33 4.33 3.74 4.34 3.97 4.32 4.67 4.00
## [331] 4.51 3.41 3.64 4.76 4.19 2.97 3.32 3.90 4.43 3.95 4.31 4.48 4.84 4.03 3.97
## [346] 3.12 4.05 3.71 3.51 3.91 4.51 3.00 3.79 4.06 3.55 4.17 4.21 3.98 2.77 5.29
## [361] 3.90 4.33 4.14 4.51 4.41

#Membangkitkan data jumlah penjualan

Y <- round(0.5*X1+2*X2+rnorm(hari, 50, 7))
Y
##   [1]  87  94  99 100  91 125  85  79  93  93  99  89  97  94  76 109  98  78
##  [19]  92  92  94  94  77  84  90  74  85 100  78 100 107  85 106  92  97  98
##  [37]  89  88  90  94  76  89  88 108 105  87  91  94  99  90  77  92  95 109
##  [55]  87 118  82  99 103  90  93 105  90  96  74  94 100  96  94 111  81  78
##  [73] 109  71  96  93  94  87  93  87  94  99  96  84  80 106 109 100  95 109
##  [91]  83 105  92  89 102  94 109 110  88  77  95 100 103  91  93 106  84  70
## [109]  88  99  89 110  77  95  96  96  96  97  87  89 100  91  85 102 106  87
## [127] 105 103  77  86  96  98  95  92  79  98  74 106 115  70  99  84  65  81
## [145]  79  88  82 105 113  78  95  99  98  77  91  97  97  85 100  97 106  93
## [163]  83 124  86 100  95  79  98 110  97 102  95 107  85  82  90 101  89  95
## [181]  90  95  95 103  87  97  97 101 101 101  85  90  90  84  77 104 102  75
## [199]  98  75 112 108  95  95  90  96  76  82 109  89 104 100 104  78  85 105
## [217]  88  79  86  75  86 101  97 103  81  74  90  93  98  88 101  92  81  95
## [235] 101  89  91  96  85  92  85  84  96  81  85 107  83  93  87 105  71  85
## [253]  85  85 117  83 104 104  93  74  95  90  86  95 127 101  79  82  92  84
## [271]  87 100 107  86  97  83  97  95 101  90  85  93  94  96 101  81  95 111
## [289]  81  98  97 109 106  93 111 100 119  95  93  88  87  88  84  88  96  92
## [307]  74  98 100 111  91  91  69  82  85 102  99  77 100  94  92 102  85  96
## [325]  74  98 101 106  99  82 119  82  86 109  85  70  71  86 101  82 102 103
## [343] 101  95  98  86  92  87  84 101 109  82  88  97  88  89  84  97  61 115
## [361]  93 103  97  96 107

#Memvisualisasi Data

##Plot Penjualan vs Pengunjung Toko

ggplot(data = data.frame(Y, X1), aes(x = X1, y = Y)) +
  geom_point() +
  labs(x = "Pengunjung Toko (perhari)", y = "Pertumbuhan Jumlah Penjualan")

##Plot Penjualan vs Kualitas Pelayanan Toko

ggplot(data = data.frame(Y, X2), aes(x = X2, y = Y)) +
  geom_point() +
  labs(x = "Kualitas Pelayanan Toko (rating 1-4)", y = "Pertumbuhan Jumlah Penjualan")

#Analisis Regresi Linear

model <- lm(Y ~ X1 + X2)
summary(model)
## 
## Call:
## lm(formula = Y ~ X1 + X2)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -19.1216  -4.6087   0.4522   4.8197  18.0019 
## 
## Coefficients:
##             Estimate Std. Error t value Pr(>|t|)
## (Intercept)  -34.418     58.582  -0.588    0.557
## X1            -1.194      1.166  -1.024    0.306
## X2            52.684     35.038   1.504    0.134
## 
## Residual standard error: 6.837 on 362 degrees of freedom
## Multiple R-squared:  0.5874, Adjusted R-squared:  0.5851 
## F-statistic: 257.7 on 2 and 362 DF,  p-value: < 2.2e-16

#Kesimpulan hasil analisis Berdasarkan hasil analisis regresi yang dipaparkan, dapat disimpulkan bahwa:

  1. Model regresi secara keseluruhan signifikan secara statistik (p-value < 2.2e-16). Ini menunjukkan bahwa ada hubungan linier antara variabel dependen (penjualan) dan setidaknya satu variabel independen (pengunjung toko atau kualitas pelayanan).
  2. Pengaruh individual variabel independen terhadap penjualan tidak signifikan secara statistik.
    • Koefisien regresi untuk pengunjung toko (X1) menunjukkan hubungan positif, namun nilai p-value (0.613) lebih besar dari 0.05.
    • Koefisien regresi untuk kualitas pelayanan (X2) menunjukkan hubungan negatif, namun nilai p-value (0.960) jauh lebih besar dari 0.05 dan nilai standar errornya sangat besar.
  3. Model regresi ini menjelaskan 56.37% variasi dalam penjualan (R-squared = 0.5637)