question The Department of Energy and the U.S. Environmental Protection Agency’s 2012 Fuel
Economy Guide provides fuel efficiency data for 2012 model year cars and trucks (Department of Energy website, April 16, 2012). The file named CarMileage provides a portion of
the data for 316 cars. The column labeled Size identifies the size of the car (Compact, Midsize, and Large) and the column labeled Hwy MPG shows the fuel efficiency rating for highway driving in terms of miles per gallon. Use $\alpha$ = .05 and test for any significant difference
in the mean fuel efficiency rating for highway driving among the three sizes of cars.
The Professional Golfers Association (PGA) maintains data on performance and earnings
for members of the PGA Tour. Based on total earnings in PGA Tour events, the top 125
players are exempt for the following season. Making the top 125 money list is important
because a player who is “exempt” has qualified to be a full-time member of the PGA Tour
for the following season.
Scoring average is generally considered the most important statistic in terms of success
on the PGATour. To investigate the relationship between scoring average and variables such
as driving distance, driving accuracy, greens in regulation, sand saves, and average putts per
round, year-end performance data for the 125 players who had the highest total earnings in
PGA Tour events for 2008 are contained in the file named PGATour (PGA Tour website,
2009). Each row of the data set corresponds to a PGA Tour player, and the data have been
sorted based upon total earnings. Descriptions for the variables in the data set follow.
Money $\,\,\,\,\,$ Total earnings in PGA Tour events.
Scoring Average $\,\,\,\,\,$ The average number of strokes per completed round.
DrDist (Driving Distance) $\,\,\,\,\,$ DrDist is the average number of yards per measured drive.
On the PGA Tour driving distance is measured on two
holes per round. Care is taken to select two holes which
face in opposite directions to counteract the effect of wind.
Drives are measured to the point at which they come to
rest regardless of whether they are in the fairway or not.
DrAccu (Driving Accuracy) $\,\,\,\,\,$ The percentage of time a tee shot comes to rest in the fairway (regardless of club). Driving accuracy is measured on
every hole, excluding par 3’s.
GIR (Greens in Regulation) $\,\,\,\,\,$ The percentage of time a player was able to hit the green
in regulation. A green is considered hit in regulation if any
portion of the ball is touching the putting surface after the
GIR stroke has been taken. The GIR stroke is determined
by subtracting 2 from par (1st stroke on a par 3, 2nd on a
par 4, 3rd on a par 5). In other words, a green is considered hit in regulation if the player has reached the putting
surface in par minus two strokes.
Sand Saves $\,\,\,\,\,$ The percentage of time a player was able to get “up and
down” once in a greenside sand bunker (regardless of score).
“Up and down” indicates it took the player 2 shots or less to
put the ball in the hole from a greenside sand bunker.
PPR (Putts per Round) $\,\,\,\,\,$ The average number of putts per round.
Scrambling $\,\,\,\,\,$ The percentage of time a player missed the green in regulation but still made par or better.
Bounce Back $\,\,\,\,\,$ The percentage of time a player is over par on a hole and
then under par on the following hole. In other words, it is
the percentage of holes with a bogey or worse followed on
the next hole with a birdie or better.