Make &Model DriveTrain MSRP Invoice EngineSi... Cylinders Horsepo... MPG_City MPG_Hi... Weight Wheelba... Length & Type & Origin 3.4 185 18 24 4431 121 201 Pontiac Montana EWB Sedan USA All 31370 28454 40075 220 18 25 4013 105 180 A4 3.0 Qualt.. Sedan Europe All 44240 27145 24687 2.5 4 185 20 27 3495 104 184 Subaru Outback Lim... Sedan Asia 15 19 3571 126 201 Mazda B4000 SE C... Truck Asia All 22350 20482 4.0 207 8: 340 15 21 3938 104 178 Audi 54 Avant Qu... Wagon Europe All 49080 14148 4.2 All 36395 33121 4.5 8 315 15 19 4309 112 189 Infiniti FX45 Wagon Asia 19 26 3779 108 182 Pontiac Aztekt SU USA Front 21595 19810 3.4 6 185 42815 394-43 4.6 302 13 18 483 114 193 Lincoln Aviator Ultim... SUV USA Front 107 193 Toyota Camry Solar... Sedan Asia Front 19635 17722 24 4 157 24 33 3175 96 167 Hyundai Accent GL 4dr Sedan Asle Front 11839 11116 1.6 4 103 29 33 2290 4 130 26 33 2606 103 168 Ford Focus SE 4dr Sedan USA Front 15460 14496 2.0 103 185 Satum lon1 4dr Sedan USA Front 10995 10319 2.2 4 140 26 35 2692 20 30 3472 114 191 BMW 5301 4dr Sedan Europe Rear 44995 41170 3.0 225 200 Infiniti Q45 Luxury ... Sedan Asia Rear 52545 47575 4.5 B 340 17 23 3977 113 BMW 3250 conve... Sedan Europe Rear 37995 34800 2.5 6 184 19 27 3560 107 177 E320 4dr Sedan Europe Roar 48170 44849 3.2 221 19 27 3635 112 190 Mercedes-B... 320 17 25 3547 106 178 Cadillac XLR converti... Sports JSA Roar 76200 70546 4.6 6 287 20 26 3428 104 169 Nissan 3502 Enthus... Sports Asia Rear 34390 31845 3.5The two variables of interest here are MPG_City and DriveTrain. The MPG variable is a measure of distance travelled per gallon of fuel used when driving in a city environment. The larger this number the more fuel efcient the vehicle is. The drive train variable indicates what wheels of the vehicle are mechanically driven from the engine. It is expected that front wheel drives have the best fuel economy, followed by rear wheel drives and then all wheel drives. This is due to the mechanical losses in the drive train. For the following, use a signicance level of 5%. (a) [2 marks] Plot the data and provide a preliminary assessment of whether there appears to be differences between fuel efciency based on drive type. (b) [6 marks] Carry out an appropriate hypothesis test to for differences in fuel efficiency for the different drive types. Make sure to report the hypotheses tested, test statistic, null distribution, pvalue and conclusion in plain language. (c) [3 marks] If appropriate, carry out post-hoe tests and report the results of each comparison making sure you justify your conclusions. If post-hoe testing is not appropriate, explain the purpose of post-hoc tests and why they are not appropriate in this example. (d) [3 marks] Assess the assumptions of the test you performed in part (b)
