Reading the data

 six_airlines <- read.csv("~/SixAirlinesDataV2.csv")
  View(six_airlines)

Describing the data

library(psych)
describe(six_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
summary(six_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
attach(six_airlines)

Box Plots

boxplot(FlightDuration~Aircraft,data=six_airlines,xlab="Aircraft type", ylab="Flight duration",col = c("green","blue"))

boxplot(FlightDuration~Airline,data=six_airlines,xlab="Airline name", ylab="Flight duration",col = c("green","blue","red"))

Scatter Plots

library(ggplot2)
## 
## Attaching package: 'ggplot2'
## The following objects are masked from 'package:psych':
## 
##     %+%, alpha
ggplot(six_airlines, aes(PricePremium, FlightDuration)) + geom_point(aes(color = Airline)) +  scale_x_continuous("Premium ticket") + scale_y_continuous("Flight duration") + theme_bw() + labs(title="Scatterplot of ticket prices") + facet_wrap( ~ TravelMonth)

ggplot(six_airlines, aes(PriceEconomy, FlightDuration)) + geom_point(aes(color = Airline)) +  scale_x_continuous("Premium ticket") + scale_y_continuous("Flight duration") + theme_bw() + labs(title="Scatterplot of ticket prices") + facet_wrap( ~ TravelMonth)

Corrgram

library(corrgram)
corrgram(six_airlines, order=NULL, panel=panel.cor,text.panel=panel.txt,main="Correlogram")

Testing & Modelling

cor.test(PriceRelative,WidthPremium)
## 
##  Pearson's product-moment correlation
## 
## data:  PriceRelative and WidthPremium
## t = 12.469, df = 456, p-value < 2.2e-16
## alternative hypothesis: true correlation is not equal to 0
## 95 percent confidence interval:
##  0.4326084 0.5695593
## sample estimates:
##       cor 
## 0.5042476
cor.test(PriceEconomy,PitchEconomy)
## 
##  Pearson's product-moment correlation
## 
## data:  PriceEconomy and PitchEconomy
## t = 8.469, df = 456, p-value = 3.428e-16
## alternative hypothesis: true correlation is not equal to 0
## 95 percent confidence interval:
##  0.2867196 0.4452479
## sample estimates:
##       cor 
## 0.3686612
library(psych)
corr.test(six_airlines[,c(6:18)])
## Call:corr.test(x = six_airlines[, c(6:18)])
## Correlation matrix 
##                     SeatsEconomy SeatsPremium PitchEconomy PitchPremium
## SeatsEconomy                1.00         0.63         0.14         0.12
## SeatsPremium                0.63         1.00        -0.03         0.00
## PitchEconomy                0.14        -0.03         1.00        -0.55
## PitchPremium                0.12         0.00        -0.55         1.00
## WidthEconomy                0.37         0.46         0.29        -0.02
## WidthPremium                0.10         0.00        -0.54         0.75
## PriceEconomy                0.13         0.11         0.37         0.05
## PricePremium                0.18         0.22         0.23         0.09
## PriceRelative               0.00        -0.10        -0.42         0.42
## SeatsTotal                  0.99         0.72         0.12         0.11
## PitchDifference             0.04         0.02        -0.78         0.95
## WidthDifference            -0.08        -0.22        -0.64         0.70
## PercentPremiumSeats        -0.33         0.49        -0.10        -0.18
##                     WidthEconomy WidthPremium PriceEconomy PricePremium
## SeatsEconomy                0.37         0.10         0.13         0.18
## SeatsPremium                0.46         0.00         0.11         0.22
## PitchEconomy                0.29        -0.54         0.37         0.23
## PitchPremium               -0.02         0.75         0.05         0.09
## WidthEconomy                1.00         0.08         0.07         0.15
## WidthPremium                0.08         1.00        -0.06         0.06
## PriceEconomy                0.07        -0.06         1.00         0.90
## PricePremium                0.15         0.06         0.90         1.00
## PriceRelative              -0.04         0.50        -0.29         0.03
## SeatsTotal                  0.41         0.09         0.13         0.19
## PitchDifference            -0.13         0.76        -0.10        -0.02
## WidthDifference            -0.39         0.88        -0.08        -0.01
## PercentPremiumSeats         0.23        -0.18         0.07         0.12
##                     PriceRelative SeatsTotal PitchDifference
## SeatsEconomy                 0.00       0.99            0.04
## SeatsPremium                -0.10       0.72            0.02
## PitchEconomy                -0.42       0.12           -0.78
## PitchPremium                 0.42       0.11            0.95
## WidthEconomy                -0.04       0.41           -0.13
## WidthPremium                 0.50       0.09            0.76
## PriceEconomy                -0.29       0.13           -0.10
## PricePremium                 0.03       0.19           -0.02
## PriceRelative                1.00      -0.01            0.47
## SeatsTotal                  -0.01       1.00            0.03
## PitchDifference              0.47       0.03            1.00
## WidthDifference              0.49      -0.11            0.76
## PercentPremiumSeats         -0.16      -0.22           -0.09
##                     WidthDifference PercentPremiumSeats
## SeatsEconomy                  -0.08               -0.33
## SeatsPremium                  -0.22                0.49
## PitchEconomy                  -0.64               -0.10
## PitchPremium                   0.70               -0.18
## WidthEconomy                  -0.39                0.23
## WidthPremium                   0.88               -0.18
## PriceEconomy                  -0.08                0.07
## PricePremium                  -0.01                0.12
## PriceRelative                  0.49               -0.16
## SeatsTotal                    -0.11               -0.22
## PitchDifference                0.76               -0.09
## WidthDifference                1.00               -0.28
## PercentPremiumSeats           -0.28                1.00
## Sample Size 
## [1] 458
## Probability values (Entries above the diagonal are adjusted for multiple tests.) 
##                     SeatsEconomy SeatsPremium PitchEconomy PitchPremium
## SeatsEconomy                0.00         0.00         0.08         0.35
## SeatsPremium                0.00         0.00         1.00         1.00
## PitchEconomy                0.00         0.47         0.00         0.00
## PitchPremium                0.01         0.92         0.00         0.00
## WidthEconomy                0.00         0.00         0.00         0.61
## WidthPremium                0.03         0.95         0.00         0.00
## PriceEconomy                0.01         0.01         0.00         0.28
## PricePremium                0.00         0.00         0.00         0.06
## PriceRelative               0.93         0.04         0.00         0.00
## SeatsTotal                  0.00         0.00         0.01         0.02
## PitchDifference             0.45         0.73         0.00         0.00
## WidthDifference             0.08         0.00         0.00         0.00
## PercentPremiumSeats         0.00         0.00         0.03         0.00
##                     WidthEconomy WidthPremium PriceEconomy PricePremium
## SeatsEconomy                0.00         0.78         0.22         0.01
## SeatsPremium                0.00         1.00         0.46         0.00
## PitchEconomy                0.00         0.00         0.00         0.00
## PitchPremium                1.00         0.00         1.00         1.00
## WidthEconomy                0.00         1.00         1.00         0.05
## WidthPremium                0.08         0.00         1.00         1.00
## PriceEconomy                0.15         0.22         0.00         0.00
## PricePremium                0.00         0.17         0.00         0.00
## PriceRelative               0.35         0.00         0.00         0.50
## SeatsTotal                  0.00         0.05         0.00         0.00
## PitchDifference             0.01         0.00         0.03         0.70
## WidthDifference             0.00         0.00         0.07         0.81
## PercentPremiumSeats         0.00         0.00         0.16         0.01
##                     PriceRelative SeatsTotal PitchDifference
## SeatsEconomy                 1.00       0.00            1.00
## SeatsPremium                 0.94       0.00            1.00
## PitchEconomy                 0.00       0.27            0.00
## PitchPremium                 0.00       0.64            0.00
## WidthEconomy                 1.00       0.00            0.22
## WidthPremium                 0.00       1.00            0.00
## PriceEconomy                 0.00       0.17            0.86
## PricePremium                 1.00       0.00            1.00
## PriceRelative                0.00       1.00            0.00
## SeatsTotal                   0.80       0.00            1.00
## PitchDifference              0.00       0.47            0.00
## WidthDifference              0.00       0.02            0.00
## PercentPremiumSeats          0.00       0.00            0.05
##                     WidthDifference PercentPremiumSeats
## SeatsEconomy                   1.00                0.00
## SeatsPremium                   0.00                0.00
## PitchEconomy                   0.00                0.78
## PitchPremium                   0.00                0.01
## WidthEconomy                   0.00                0.00
## WidthPremium                   0.00                0.00
## PriceEconomy                   1.00                1.00
## PricePremium                   1.00                0.41
## PriceRelative                  0.00                0.02
## SeatsTotal                     0.68                0.00
## PitchDifference                0.00                1.00
## WidthDifference                0.00                0.00
## PercentPremiumSeats            0.00                0.00
## 
##  To see confidence intervals of the correlations, print with the short=FALSE option
m1 <- lm(PriceRelative ~ PitchEconomy + PitchPremium + WidthPremium + PriceEconomy + PitchDifference + WidthDifference + PercentPremiumSeats, data = six_airlines)
summary(m1)
## 
## Call:
## lm(formula = PriceRelative ~ PitchEconomy + PitchPremium + WidthPremium + 
##     PriceEconomy + PitchDifference + WidthDifference + PercentPremiumSeats, 
##     data = six_airlines)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.90093 -0.22133 -0.02915  0.15791  1.16165 
## 
## Coefficients: (1 not defined because of singularities)
##                       Estimate Std. Error t value Pr(>|t|)    
## (Intercept)         -1.102e+00  1.752e+00  -0.629 0.529437    
## PitchEconomy        -6.810e-02  4.511e-02  -1.510 0.131826    
## PitchPremium         3.359e-02  2.192e-02   1.533 0.126056    
## WidthPremium         1.371e-01  3.827e-02   3.583 0.000377 ***
## PriceEconomy        -1.056e-04  2.085e-05  -5.064 5.99e-07 ***
## PitchDifference             NA         NA      NA       NA    
## WidthDifference      7.238e-03  3.769e-02   0.192 0.847790    
## PercentPremiumSeats -6.789e-03  4.267e-03  -1.591 0.112312    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.3688 on 451 degrees of freedom
## Multiple R-squared:  0.339,  Adjusted R-squared:  0.3302 
## F-statistic: 38.56 on 6 and 451 DF,  p-value: < 2.2e-16
m2 <- lm(PriceRelative ~ PitchDifference + WidthPremium + PriceEconomy)
coefficients(m2)
##     (Intercept) PitchDifference    WidthPremium    PriceEconomy 
##   -2.5405744540    0.0432138143    0.1484583578   -0.0001144987

Observation

The Null hypothesis states that there is no significant correlation between relative price and width of premium class seats and there is no significant correlation between price of economy tickets and the pitch of economy class seats.But both the Null hypothesis are rejected as the p value << 0.05 and relative price mainly depends on the width of premium class seats and pitch difference.