Six <- read.csv(paste("SixAirlinesDataV2.csv", sep=""))
View(Six)
summary(Six)
##       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
library(psych)
describe(Six)
##                     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(Six)

attach(Six)

Comparison of No. of Economy Seats to No. of Premium Seats

par(mfrow=c(1,2))
hist(SeatsEconomy,main="Economy Class Seats",col='blue')
hist(SeatsPremium, main="Premium Class Seats",col='blue')

par(mfrow=c(1,2))
boxplot(SeatsEconomy,col='blue',xlab="Economy Seats")
boxplot(SeatsPremium,col='blue', xlab="Premium Seats")

Comparison of Economy Seat Pitch with Premium Seat Pitch

par(mfrow=c(1,2))
hist(PitchEconomy,main="Economy Class Seat Pitch",col='blue')
hist(PitchPremium, main="Premium Class Seat Pitch",col='blue')

par(mfrow=c(1,2))
boxplot(PitchEconomy,col='blue',xlab="Pitch of Economy Seats")
boxplot(PitchPremium,col='blue', xlab="Pitch of Premium Seats")

Comparison of Economy Seat Width with Premium Seat Width

par(mfrow=c(1,2))
hist(WidthEconomy,main="Economy Class Seat Width",col='blue')
hist(WidthPremium, main="Premium Class Seat Width",col='blue')

par(mfrow=c(1,2))
boxplot(WidthEconomy,col='blue',xlab="Width of Economy Seats")
boxplot(WidthPremium,col='blue', xlab="Width of Premium Seats")

Comparison of Economy Seat Price with Premium Seat Price

par(mfrow=c(1,2))
hist(PriceEconomy,main="Economy Class Seat Price",col='blue')
hist(PricePremium, main="Premium Class Seat Price",col='blue')

par(mfrow=c(1,2))
boxplot(PriceEconomy,col='blue',xlab="Price of Economy Seats")
boxplot(PricePremium,col='blue', xlab="Price of Premium Seats")

library(car)
## 
## Attaching package: 'car'
## The following object is masked from 'package:psych':
## 
##     logit

Scatterplot for Relative Price vs Percent Premium Seats

scatterplot(PriceRelative~PercentPremiumSeats,spread=FALSE, main="Relative Price vs Percent Premium Seats",xlab="Percent Premium Seats",ylab='Relative Price')

Scatterplot for Relative Price vs Width Difference

scatterplot(PriceRelative~WidthDifference,spread=FALSE, main="Relative Price vs Width Difference",xlab="Percent Premium Seats",ylab='Relative Price')

Scatterplot for Relative Price vs Pitch Difference

scatterplot(PriceRelative~PitchDifference,spread=FALSE, main="Relative Price vs Pitch Difference",xlab="Percent Premium Seats",ylab='Relative Price')

ScatterplotMatrix of Relative Price, Pitch Difference and Width Difference

scatterplotMatrix(~PriceRelative+PitchDifference+WidthDifference,data = Six, diagonal='histogram')

library(corrgram)
corrgram(Six,
         main="Premium Class Analysis in Various Factors",
         lower.panel=panel.shade, upper.panel=panel.pie,
         diag.panel=panel.minmax, text.panel=panel.txt)

cor(Six[,6:18])
##                     SeatsEconomy SeatsPremium PitchEconomy PitchPremium
## SeatsEconomy         1.000000000  0.625056587   0.14412692  0.119221250
## SeatsPremium         0.625056587  1.000000000  -0.03421296  0.004883123
## PitchEconomy         0.144126924 -0.034212963   1.00000000 -0.550606241
## PitchPremium         0.119221250  0.004883123  -0.55060624  1.000000000
## WidthEconomy         0.373670252  0.455782883   0.29448586 -0.023740873
## WidthPremium         0.102431959 -0.002717527  -0.53929285  0.750259029
## PriceEconomy         0.128167220  0.113642176   0.36866123  0.050384550
## PricePremium         0.177000928  0.217612376   0.22614179  0.088539147
## PriceRelative        0.003956939 -0.097196009  -0.42302204  0.417539056
## SeatsTotal           0.992607966  0.715171053   0.12373524  0.107512784
## PitchDifference      0.035318044  0.016365566  -0.78254993  0.950591466
## WidthDifference     -0.080670148 -0.216168666  -0.63557430  0.703281797
## PercentPremiumSeats -0.330935223  0.485029771  -0.10280880 -0.175487414
##                     WidthEconomy WidthPremium PriceEconomy PricePremium
## SeatsEconomy          0.37367025  0.102431959   0.12816722   0.17700093
## SeatsPremium          0.45578288 -0.002717527   0.11364218   0.21761238
## PitchEconomy          0.29448586 -0.539292852   0.36866123   0.22614179
## PitchPremium         -0.02374087  0.750259029   0.05038455   0.08853915
## WidthEconomy          1.00000000  0.081918728   0.06799061   0.15054837
## WidthPremium          0.08191873  1.000000000  -0.05704522   0.06402004
## PriceEconomy          0.06799061 -0.057045224   1.00000000   0.90138870
## PricePremium          0.15054837  0.064020043   0.90138870   1.00000000
## PriceRelative        -0.04396116  0.504247591  -0.28856711   0.03184654
## SeatsTotal            0.40545860  0.091297500   0.13243313   0.19232533
## PitchDifference      -0.12722421  0.760121272  -0.09952511  -0.01806629
## WidthDifference      -0.39320512  0.884149655  -0.08449975  -0.01151218
## PercentPremiumSeats   0.22714172 -0.183312058   0.06532232   0.11639097
##                     PriceRelative  SeatsTotal PitchDifference
## SeatsEconomy          0.003956939  0.99260797      0.03531804
## SeatsPremium         -0.097196009  0.71517105      0.01636557
## PitchEconomy         -0.423022038  0.12373524     -0.78254993
## PitchPremium          0.417539056  0.10751278      0.95059147
## WidthEconomy         -0.043961160  0.40545860     -0.12722421
## WidthPremium          0.504247591  0.09129750      0.76012127
## PriceEconomy         -0.288567110  0.13243313     -0.09952511
## PricePremium          0.031846537  0.19232533     -0.01806629
## PriceRelative         1.000000000 -0.01156894      0.46873025
## SeatsTotal           -0.011568942  1.00000000      0.03416915
## PitchDifference       0.468730249  0.03416915      1.00000000
## WidthDifference       0.485802437 -0.10584398      0.76089108
## PercentPremiumSeats  -0.161565556 -0.22091465     -0.09264869
##                     WidthDifference PercentPremiumSeats
## 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
cor(PriceRelative,PitchDifference)
## [1] 0.4687302
cor(PriceRelative,WidthDifference)
## [1] 0.4858024
cor(PriceRelative,PricePremium)
## [1] 0.03184654
cor(PriceRelative, PriceEconomy)
## [1] -0.2885671
cor(PriceRelative,PercentPremiumSeats)
## [1] -0.1615656

Appropriate t-test

t.test(PriceRelative~Aircraft,Six)
## 
##  Welch Two Sample t-test
## 
## data:  PriceRelative by Aircraft
## t = -2.6145, df = 363.72, p-value = 0.009306
## alternative hypothesis: true difference in means is not equal to 0
## 95 percent confidence interval:
##  -0.18934647 -0.02678486
## sample estimates:
## mean in group AirBus mean in group Boeing 
##            0.4147682            0.5228339

Corr Test

cor.test(PriceRelative,PitchDifference,method="pearson")
## 
##  Pearson's product-moment correlation
## 
## data:  PriceRelative and PitchDifference
## t = 11.331, df = 456, p-value < 2.2e-16
## alternative hypothesis: true correlation is not equal to 0
## 95 percent confidence interval:
##  0.3940262 0.5372817
## sample estimates:
##       cor 
## 0.4687302
cor.test(PriceRelative,WidthDifference,method="pearson")
## 
##  Pearson's product-moment correlation
## 
## data:  PriceRelative and WidthDifference
## t = 11.869, df = 456, p-value < 2.2e-16
## alternative hypothesis: true correlation is not equal to 0
## 95 percent confidence interval:
##  0.4125388 0.5528218
## sample estimates:
##       cor 
## 0.4858024
cor.test(PriceRelative,SeatsEconomy,method="pearson")
## 
##  Pearson's product-moment correlation
## 
## data:  PriceRelative and SeatsEconomy
## t = 0.084498, df = 456, p-value = 0.9327
## alternative hypothesis: true correlation is not equal to 0
## 95 percent confidence interval:
##  -0.08770167  0.09554911
## sample estimates:
##         cor 
## 0.003956939
cor.test(PriceRelative,SeatsPremium,method="pearson")
## 
##  Pearson's product-moment correlation
## 
## data:  PriceRelative and SeatsPremium
## t = -2.0854, df = 456, p-value = 0.03759
## alternative hypothesis: true correlation is not equal to 0
## 95 percent confidence interval:
##  -0.18715605 -0.00561924
## sample estimates:
##         cor 
## -0.09719601

Regration Model

fit <- lm(PriceRelative ~ Airline+Aircraft+FlightDuration+TravelMonth+IsInternational+SeatsEconomy+SeatsPremium+PitchEconomy+PitchPremium+WidthEconomy+WidthPremium+PriceEconomy+PricePremium +PercentPremiumSeats+PitchDifference+WidthDifference+SeatsTotal, data =Six)
summary(fit)
## 
## Call:
## lm(formula = PriceRelative ~ Airline + Aircraft + FlightDuration + 
##     TravelMonth + IsInternational + SeatsEconomy + SeatsPremium + 
##     PitchEconomy + PitchPremium + WidthEconomy + WidthPremium + 
##     PriceEconomy + PricePremium + PercentPremiumSeats + PitchDifference + 
##     WidthDifference + SeatsTotal, data = Six)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.76373 -0.08269  0.00438  0.08002  0.84672 
## 
## Coefficients: (3 not defined because of singularities)
##                                Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                  -3.993e-01  2.948e+00  -0.135 0.892302    
## AirlineBritish               -3.971e-01  1.107e-01  -3.586 0.000373 ***
## AirlineDelta                 -3.865e-01  2.203e-01  -1.755 0.080020 .  
## AirlineJet                   -2.584e-01  9.594e-02  -2.693 0.007354 ** 
## AirlineSingapore             -3.535e-01  1.297e-01  -2.725 0.006685 ** 
## AirlineVirgin                -3.575e-01  2.031e-01  -1.761 0.078997 .  
## AircraftBoeing                4.003e-02  2.968e-02   1.349 0.178089    
## FlightDuration                2.613e-02  4.727e-03   5.526 5.63e-08 ***
## TravelMonthJul                2.111e-02  3.145e-02   0.671 0.502475    
## TravelMonthOct                2.778e-02  2.670e-02   1.041 0.298619    
## TravelMonthSep               -6.617e-03  2.664e-02  -0.248 0.803924    
## IsInternationalInternational  2.785e-02  2.502e-01   0.111 0.911400    
## SeatsEconomy                  8.090e-04  5.462e-04   1.481 0.139313    
## SeatsPremium                 -7.374e-03  3.615e-03  -2.040 0.041967 *  
## PitchEconomy                 -1.756e-02  7.994e-02  -0.220 0.826207    
## PitchPremium                  5.960e-02  9.165e-02   0.650 0.515823    
## WidthEconomy                 -9.207e-02  5.266e-02  -1.748 0.081085 .  
## WidthPremium                  4.904e-02  1.365e-01   0.359 0.719527    
## PriceEconomy                 -9.325e-04  3.318e-05 -28.105  < 2e-16 ***
## PricePremium                  5.781e-04  2.294e-05  25.197  < 2e-16 ***
## PercentPremiumSeats           1.114e-02  7.653e-03   1.456 0.146197    
## PitchDifference                      NA         NA      NA       NA    
## WidthDifference                      NA         NA      NA       NA    
## SeatsTotal                           NA         NA      NA       NA    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.2123 on 437 degrees of freedom
## Multiple R-squared:  0.7878, Adjusted R-squared:  0.7781 
## F-statistic: 81.12 on 20 and 437 DF,  p-value: < 2.2e-16

The variables AirlineBritish, AirlineJet, AirlineSingapore, FlightDuration, TravelMonthOct, SeatsPremium, WidthEconomy, PriceEconomy and PricePremium are statically significant as their p-value < 0.05. Null hypothesis is rejected. The number of economy seats are much higher than the number of premium seats. We can also interpret that premium seats price has a positive effect on the relative price. From the above analysis the price of premium seats is greater than the price of economy seats due to more pitch and width in premium seats. Relative price mainly depends on the width of premium class seats and pitch difference.

fit<- lm(PriceRelative~PitchDifference+WidthDifference,Six)
summary(fit)
## 
## Call:
## lm(formula = PriceRelative ~ PitchDifference + WidthDifference, 
##     data = Six)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.84163 -0.28484 -0.07241  0.17698  1.18778 
## 
## Coefficients:
##                 Estimate Std. Error t value Pr(>|t|)    
## (Intercept)     -0.10514    0.08304  -1.266 0.206077    
## PitchDifference  0.06019    0.01590   3.785 0.000174 ***
## WidthDifference  0.11621    0.02356   4.933 1.14e-06 ***
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.3886 on 455 degrees of freedom
## Multiple R-squared:  0.2593, Adjusted R-squared:  0.2561 
## F-statistic: 79.65 on 2 and 455 DF,  p-value: < 2.2e-16

We can reject the null hypothesis as both the p value are less than 0.05.It implies that both pitch difference and width difference have impact on relative price of the ticket.