Reading Dataset

airlines <- read.csv('SixAirlinesDataV2.csv')

Summarising data

summary(airlines)
##       Airline      Aircraft   FlightDuration   TravelMonth
##  AirFrance: 74   AirBus:151   Min.   : 1.250   Aug:127    
##  British  :175   Boeing:307   1st Qu.: 4.260   Jul: 75    
##  Delta    : 46                Median : 7.790   Oct:127    
##  Jet      : 61                Mean   : 7.578   Sep:129    
##  Singapore: 40                3rd Qu.:10.620              
##  Virgin   : 62                Max.   :14.660              
##       IsInternational  SeatsEconomy    SeatsPremium    PitchEconomy  
##  Domestic     : 40    Min.   : 78.0   Min.   : 8.00   Min.   :30.00  
##  International:418    1st Qu.:133.0   1st Qu.:21.00   1st Qu.:31.00  
##                       Median :185.0   Median :36.00   Median :31.00  
##                       Mean   :202.3   Mean   :33.65   Mean   :31.22  
##                       3rd Qu.:243.0   3rd Qu.:40.00   3rd Qu.:32.00  
##                       Max.   :389.0   Max.   :66.00   Max.   :33.00  
##   PitchPremium    WidthEconomy    WidthPremium    PriceEconomy 
##  Min.   :34.00   Min.   :17.00   Min.   :17.00   Min.   :  65  
##  1st Qu.:38.00   1st Qu.:18.00   1st Qu.:19.00   1st Qu.: 413  
##  Median :38.00   Median :18.00   Median :19.00   Median :1242  
##  Mean   :37.91   Mean   :17.84   Mean   :19.47   Mean   :1327  
##  3rd Qu.:38.00   3rd Qu.:18.00   3rd Qu.:21.00   3rd Qu.:1909  
##  Max.   :40.00   Max.   :19.00   Max.   :21.00   Max.   :3593  
##   PricePremium    PriceRelative      SeatsTotal  PitchDifference 
##  Min.   :  86.0   Min.   :0.0200   Min.   : 98   Min.   : 2.000  
##  1st Qu.: 528.8   1st Qu.:0.1000   1st Qu.:166   1st Qu.: 6.000  
##  Median :1737.0   Median :0.3650   Median :227   Median : 7.000  
##  Mean   :1845.3   Mean   :0.4872   Mean   :236   Mean   : 6.688  
##  3rd Qu.:2989.0   3rd Qu.:0.7400   3rd Qu.:279   3rd Qu.: 7.000  
##  Max.   :7414.0   Max.   :1.8900   Max.   :441   Max.   :10.000  
##  WidthDifference PercentPremiumSeats
##  Min.   :0.000   Min.   : 4.71      
##  1st Qu.:1.000   1st Qu.:12.28      
##  Median :1.000   Median :13.21      
##  Mean   :1.633   Mean   :14.65      
##  3rd Qu.:3.000   3rd Qu.:15.36      
##  Max.   :4.000   Max.   :24.69

Describing Data

library(psych)
## Warning: package 'psych' was built under R version 3.4.3
describe(airlines)
##                     vars   n    mean      sd  median trimmed     mad   min
## Airline*               1 458    3.01    1.65    2.00    2.89    1.48  1.00
## Aircraft*              2 458    1.67    0.47    2.00    1.71    0.00  1.00
## FlightDuration         3 458    7.58    3.54    7.79    7.57    4.81  1.25
## TravelMonth*           4 458    2.56    1.17    3.00    2.58    1.48  1.00
## IsInternational*       5 458    1.91    0.28    2.00    2.00    0.00  1.00
## SeatsEconomy           6 458  202.31   76.37  185.00  194.64   85.99 78.00
## SeatsPremium           7 458   33.65   13.26   36.00   33.35   11.86  8.00
## PitchEconomy           8 458   31.22    0.66   31.00   31.26    0.00 30.00
## PitchPremium           9 458   37.91    1.31   38.00   38.05    0.00 34.00
## WidthEconomy          10 458   17.84    0.56   18.00   17.81    0.00 17.00
## WidthPremium          11 458   19.47    1.10   19.00   19.53    0.00 17.00
## PriceEconomy          12 458 1327.08  988.27 1242.00 1244.40 1159.39 65.00
## PricePremium          13 458 1845.26 1288.14 1737.00 1799.05 1845.84 86.00
## PriceRelative         14 458    0.49    0.45    0.36    0.42    0.41  0.02
## SeatsTotal            15 458  235.96   85.29  227.00  228.73   90.44 98.00
## PitchDifference       16 458    6.69    1.76    7.00    6.76    0.00  2.00
## WidthDifference       17 458    1.63    1.19    1.00    1.53    0.00  0.00
## PercentPremiumSeats   18 458   14.65    4.84   13.21   14.31    2.68  4.71
##                         max   range  skew kurtosis    se
## Airline*               6.00    5.00  0.61    -0.95  0.08
## Aircraft*              2.00    1.00 -0.72    -1.48  0.02
## FlightDuration        14.66   13.41 -0.07    -1.12  0.17
## TravelMonth*           4.00    3.00 -0.14    -1.46  0.05
## IsInternational*       2.00    1.00 -2.91     6.50  0.01
## SeatsEconomy         389.00  311.00  0.72    -0.36  3.57
## SeatsPremium          66.00   58.00  0.23    -0.46  0.62
## PitchEconomy          33.00    3.00 -0.03    -0.35  0.03
## PitchPremium          40.00    6.00 -1.51     3.52  0.06
## WidthEconomy          19.00    2.00 -0.04    -0.08  0.03
## WidthPremium          21.00    4.00 -0.08    -0.31  0.05
## PriceEconomy        3593.00 3528.00  0.51    -0.88 46.18
## PricePremium        7414.00 7328.00  0.50     0.43 60.19
## PriceRelative          1.89    1.87  1.17     0.72  0.02
## SeatsTotal           441.00  343.00  0.70    -0.53  3.99
## PitchDifference       10.00    8.00 -0.54     1.78  0.08
## WidthDifference        4.00    4.00  0.84    -0.53  0.06
## PercentPremiumSeats   24.69   19.98  0.71     0.28  0.23

BoxPlot

boxplot(airlines$FlightDuration, 
        main="FlightDuration", 
        xlab="Number")

boxplot(airlines$SeatsEconomy, 
        main="SeatsEconomy", 
        xlab="Number")

boxplot(airlines$SeatsPremium, 
        main="SeatsPremium", 
        xlab="Number")

boxplot(airlines$PitchEconomy, 
        main="PitchEconomy", 
        xlab="Number")

boxplot(airlines$PitchPremium, 
        main="PitchPremium", 
        xlab="Number")

boxplot(airlines$WidthEconomy, 
        main="WidthEconomy", 
        xlab="Number")

boxplot(airlines$WidthPremium, 
        main="WidthPremium", 
        xlab="Number")

boxplot(airlines$PriceEconomy, 
        main="PriceEconomy", 
        xlab="Number")

boxplot(airlines$PricePremium, 
        main="PricePremium", 
        xlab="Number")

boxplot(airlines$PriceRelative, 
        main="PriceRelative", 
        xlab="Number")

boxplot(airlines$SeatsTotal, 
        main="SeatsTotal", 
        xlab="Number")

boxplot(airlines$PitchDifference, 
        main="PitchDifference", 
        xlab="Number")

boxplot(airlines$WidthDifference, 
        main="WidthDifference", 
        xlab="Number")

boxplot(airlines$PercentPremiumSeats, 
        main="PercentPremiumSeats", 
        xlab="Number")

#BarPlots

counts <- table(airlines$FlightDuration)
barplot(counts, main="Analising", 
        xlab="Flight Duration")

#ScatterPlot

pairs(~ FlightDuration + SeatsEconomy
 + SeatsPremium +   PitchEconomy +  PitchPremium +  WidthEconomy +  WidthPremium +  PriceEconomy +  PricePremium +  PriceRelative + SeatsTotal +    PitchDifference +   WidthDifference +   PercentPremiumSeats
,data=airlines, main="Simple Scatterplot Matrix")

#Corrgram

library(corrgram)
## Warning: package 'corrgram' was built under R version 3.4.3
corrgram(airlines, order=TRUE, lower.panel=panel.shade,
         upper.panel=panel.pie, text.panel=panel.txt,
         main="Car Milage Data in PC2/PC1 Order")

library(corpcor)
library(tseries)
## Warning: package 'tseries' was built under R version 3.4.3
al <- as.matrix(airlines[,c(3,6:18)])
covmat = cov(al)
covmat
##                     FlightDuration  SeatsEconomy  SeatsPremium
## FlightDuration          12.5462183    52.9194291    7.57372426
## SeatsEconomy            52.9194291  5832.9154300  633.07060954
## SeatsPremium             7.5737243   633.0706095  175.86521648
## PitchEconomy             0.6817421     7.2117665   -0.29725856
## PitchPremium             0.4477835    11.9637325    0.08508595
## WidthEconomy             0.9014224    15.9105138    3.36977440
## WidthPremium             0.4019845     8.5832800   -0.03954019
## PriceEconomy          1983.5401655  9673.7944684 1489.38359627
## PricePremium          2959.9783043 17413.2541733 3717.36428960
## PriceRelative            0.1932368     0.1361699   -0.58078765
## SeatsTotal              60.4931534  6465.9860396  808.93582602
## PitchDifference         -0.2339587     4.7519660    0.38234451
## WidthDifference         -0.4994380    -7.3272338   -3.40931459
## PercentPremiumSeats      1.0379912  -122.3914537   31.14753127
##                     PitchEconomy PitchPremium WidthEconomy WidthPremium
## FlightDuration         0.6817421   0.44778348   0.90142242   0.40198446
## SeatsEconomy           7.2117665  11.96373253  15.91051379   8.58327998
## SeatsPremium          -0.2972586   0.08508595   3.36977440  -0.03954019
## PitchEconomy           0.4292471  -0.47398546   0.10756500  -0.38766208
## PitchPremium          -0.4739855   1.72639580  -0.01739081   1.08157435
## WidthEconomy           0.1075650  -0.01739081   0.31081765   0.05010845
## WidthPremium          -0.3876621   1.08157435   0.05010845   1.20378776
## PriceEconomy         238.7031905  65.42513354  37.46095191 -61.85450011
## PricePremium         190.8517195 149.85356368 108.11611707  90.47997668
## PriceRelative         -0.1248808   0.24719874  -0.01104335   0.24928593
## SeatsTotal             6.9145079  12.04881848  19.28028819   8.54373979
## PitchDifference       -0.9032326   2.20038126  -0.12495581   1.46923643
## WidthDifference       -0.4952271   1.09896515  -0.26070920   1.15367930
## PercentPremiumSeats   -0.3261739  -1.11655834   0.61321816  -0.97393787
##                      PriceEconomy  PricePremium PriceRelative
## FlightDuration         1983.54017    2959.97830    0.19323683
## SeatsEconomy           9673.79447   17413.25417    0.13616991
## SeatsPremium           1489.38360    3717.36429   -0.58078765
## PitchEconomy            238.70319     190.85172   -0.12488080
## PitchPremium             65.42513     149.85356    0.24719874
## WidthEconomy             37.46095     108.11612   -0.01104335
## WidthPremium            -61.85450      90.47998    0.24928593
## PriceEconomy         976684.06198 1147494.76801 -128.49991725
## PricePremium        1147494.76801 1659293.11947   18.48428836
## PriceRelative          -128.49992      18.48429    0.20302893
## SeatsTotal            11163.17806   21130.61846   -0.44461774
## PitchDifference        -173.27806     -40.99816    0.37207954
## WidthDifference         -99.31545     -17.63614    0.26032928
## PercentPremiumSeats     312.61077     726.01582   -0.35252750
##                        SeatsTotal PitchDifference WidthDifference
## FlightDuration         60.4931534      -0.2339587      -0.4994380
## SeatsEconomy         6465.9860396       4.7519660      -7.3272338
## SeatsPremium          808.9358260       0.3823445      -3.4093146
## PitchEconomy            6.9145079      -0.9032326      -0.4952271
## PitchPremium           12.0488185       2.2003813       1.0989652
## WidthEconomy           19.2802882      -0.1249558      -0.2607092
## WidthPremium            8.5437398       1.4692364       1.1536793
## PriceEconomy        11163.1780647    -173.2780570     -99.3154520
## PricePremium        21130.6184629     -40.9981558     -17.6361404
## PriceRelative          -0.4446177       0.3720795       0.2603293
## SeatsTotal           7274.9218656       5.1343105     -10.7365484
## PitchDifference         5.1343105       3.1036138       1.5941922
## WidthDifference       -10.7365484       1.5941922       1.4143885
## PercentPremiumSeats   -91.2439224      -0.7903844      -1.5871560
##                     PercentPremiumSeats
## FlightDuration                1.0379912
## SeatsEconomy               -122.3914537
## SeatsPremium                 31.1475313
## PitchEconomy                 -0.3261739
## PitchPremium                 -1.1165583
## WidthEconomy                  0.6132182
## WidthPremium                 -0.9739379
## PriceEconomy                312.6107669
## PricePremium                726.0158229
## PriceRelative                -0.3525275
## SeatsTotal                  -91.2439224
## PitchDifference              -0.7903844
## WidthDifference              -1.5871560
## PercentPremiumSeats          23.4493343
cov2cor(covmat)
##                     FlightDuration SeatsEconomy SeatsPremium PitchEconomy
## FlightDuration          1.00000000  0.195621187  0.161236400   0.29377174
## SeatsEconomy            0.19562119  1.000000000  0.625056587   0.14412692
## SeatsPremium            0.16123640  0.625056587  1.000000000  -0.03421296
## PitchEconomy            0.29377174  0.144126924 -0.034212963   1.00000000
## PitchPremium            0.09621471  0.119221250  0.004883123  -0.55060624
## WidthEconomy            0.45647720  0.373670252  0.455782883   0.29448586
## WidthPremium            0.10343747  0.102431959 -0.002717527  -0.53929285
## PriceEconomy            0.56664039  0.128167220  0.113642176   0.36866123
## PricePremium            0.64873981  0.177000928  0.217612376   0.22614179
## PriceRelative           0.12107501  0.003956939 -0.097196009  -0.42302204
## SeatsTotal              0.20023299  0.992607966  0.715171053   0.12373524
## PitchDifference        -0.03749288  0.035318044  0.016365566  -0.78254993
## WidthDifference        -0.11856070 -0.080670148 -0.216168666  -0.63557430
## PercentPremiumSeats     0.06051625 -0.330935223  0.485029771  -0.10280880
##                     PitchPremium WidthEconomy WidthPremium PriceEconomy
## FlightDuration       0.096214708   0.45647720  0.103437469   0.56664039
## SeatsEconomy         0.119221250   0.37367025  0.102431959   0.12816722
## SeatsPremium         0.004883123   0.45578288 -0.002717527   0.11364218
## PitchEconomy        -0.550606241   0.29448586 -0.539292852   0.36866123
## PitchPremium         1.000000000  -0.02374087  0.750259029   0.05038455
## WidthEconomy        -0.023740873   1.00000000  0.081918728   0.06799061
## WidthPremium         0.750259029   0.08191873  1.000000000  -0.05704522
## PriceEconomy         0.050384550   0.06799061 -0.057045224   1.00000000
## PricePremium         0.088539147   0.15054837  0.064020043   0.90138870
## PriceRelative        0.417539056  -0.04396116  0.504247591  -0.28856711
## SeatsTotal           0.107512784   0.40545860  0.091297500   0.13243313
## PitchDifference      0.950591466  -0.12722421  0.760121272  -0.09952511
## WidthDifference      0.703281797  -0.39320512  0.884149655  -0.08449975
## PercentPremiumSeats -0.175487414   0.22714172 -0.183312058   0.06532232
##                     PricePremium PriceRelative  SeatsTotal PitchDifference
## FlightDuration        0.64873981   0.121075014  0.20023299     -0.03749288
## SeatsEconomy          0.17700093   0.003956939  0.99260797      0.03531804
## SeatsPremium          0.21761238  -0.097196009  0.71517105      0.01636557
## PitchEconomy          0.22614179  -0.423022038  0.12373524     -0.78254993
## PitchPremium          0.08853915   0.417539056  0.10751278      0.95059147
## WidthEconomy          0.15054837  -0.043961160  0.40545860     -0.12722421
## WidthPremium          0.06402004   0.504247591  0.09129750      0.76012127
## PriceEconomy          0.90138870  -0.288567110  0.13243313     -0.09952511
## PricePremium          1.00000000   0.031846537  0.19232533     -0.01806629
## PriceRelative         0.03184654   1.000000000 -0.01156894      0.46873025
## SeatsTotal            0.19232533  -0.011568942  1.00000000      0.03416915
## PitchDifference      -0.01806629   0.468730249  0.03416915      1.00000000
## WidthDifference      -0.01151218   0.485802437 -0.10584398      0.76089108
## PercentPremiumSeats   0.11639097  -0.161565556 -0.22091465     -0.09264869
##                     WidthDifference PercentPremiumSeats
## FlightDuration          -0.11856070          0.06051625
## SeatsEconomy            -0.08067015         -0.33093522
## SeatsPremium            -0.21616867          0.48502977
## PitchEconomy            -0.63557430         -0.10280880
## PitchPremium             0.70328180         -0.17548741
## WidthEconomy            -0.39320512          0.22714172
## WidthPremium             0.88414965         -0.18331206
## PriceEconomy            -0.08449975          0.06532232
## PricePremium            -0.01151218          0.11639097
## PriceRelative            0.48580244         -0.16156556
## SeatsTotal              -0.10584398         -0.22091465
## PitchDifference          0.76089108         -0.09264869
## WidthDifference          1.00000000         -0.27559416
## PercentPremiumSeats     -0.27559416          1.00000000

Linear Regression Model

a <- lm( formula = PriceRelative ~ SeatsEconomy +SeatsPremium+  PitchEconomy+   PitchPremium+   WidthEconomy+   WidthPremium+   PriceEconomy+   PricePremium+
    FlightDuration+SeatsTotal   +PitchDifference+   WidthDifference +PercentPremiumSeats , data = airlines)
summary(a)
## 
## Call:
## lm(formula = PriceRelative ~ SeatsEconomy + SeatsPremium + PitchEconomy + 
##     PitchPremium + WidthEconomy + WidthPremium + PriceEconomy + 
##     PricePremium + FlightDuration + SeatsTotal + PitchDifference + 
##     WidthDifference + PercentPremiumSeats, data = airlines)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.77611 -0.10464  0.00752  0.07428  0.84432 
## 
## Coefficients: (3 not defined because of singularities)
##                       Estimate Std. Error t value Pr(>|t|)    
## (Intercept)         -5.091e+00  1.108e+00  -4.594 5.66e-06 ***
## SeatsEconomy         1.768e-03  5.264e-04   3.358 0.000851 ***
## SeatsPremium        -1.501e-02  3.131e-03  -4.793 2.25e-06 ***
## PitchEconomy         1.085e-01  2.824e-02   3.840 0.000141 ***
## PitchPremium         1.151e-01  1.349e-02   8.530 2.28e-16 ***
## WidthEconomy        -1.998e-01  2.878e-02  -6.940 1.39e-11 ***
## WidthPremium         5.969e-02  1.602e-02   3.725 0.000220 ***
## PriceEconomy        -8.462e-04  2.939e-05 -28.788  < 2e-16 ***
## PricePremium         5.500e-04  2.253e-05  24.410  < 2e-16 ***
## FlightDuration       2.163e-02  4.490e-03   4.817 2.00e-06 ***
## SeatsTotal                  NA         NA      NA       NA    
## PitchDifference             NA         NA      NA       NA    
## WidthDifference             NA         NA      NA       NA    
## PercentPremiumSeats  2.211e-02  7.480e-03   2.956 0.003285 ** 
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2187 on 447 degrees of freedom
## Multiple R-squared:  0.7695, Adjusted R-squared:  0.7643 
## F-statistic: 149.2 on 10 and 447 DF,  p-value: < 2.2e-16