For the roller coaster data in Exercise 47:
a) Explain why in looking for a variable that explains rank, you will be hoping for a negative correlation.
b) Do any of the provided variables provide a strong predictor for roller coaster rank?
c) What other (unaccounted) for variables might help explain the rank?

Max Vert Max Speed Angle Length Location Drop((sec) Height ft.) (mphdegrees) (ft.) Initial Duration Park Rank Roller Coaster 5400 4003 5100 2454 2349 2477 155 72 221 184 300 208 188 Six Flags New England MA 1Bizarro 2 Expedition GeforceHoliday Park 3 Intimidator 305 KingsDominion 74.6 85 67.4 108 54 Tobu Zoo Alton Towers Djurs Sommerland Walibi World 4 Kawasemi 50 104 100 152 300 148 181 UK 5 Nemesis 6 Piraten 7 Goliath 8 Millennium Force Cedar Point 9 Katurn 10 Speerd 105 155 310 169 180 66.9 93 65 74.6 120 142 60 6595 3937 3281 Mirabilandia Mirabilandia 90