Does elevation impact hitting performance in baseball?

The Colorado Rockies play their major league home baseball games in Coors Field, Denver. Each year, the Rockies are among the leaders in team batting statistics (e.g., home runs, batting average, and slugging percentage). Many baseball experts attribute this phenomenon to the “thin air”

of Denver—called the “mile-high city” due to its elevation.

Chance (Winter 2006) investigated the effects of elevation on slugging percentage in Major League Baseball. Data were compiled on players’ composite slugging percentage at each of 29 cities for a recent season as well as each city’s elevation (feet above sea level). (Selected observations are shown in the next table.) Construct a scatterplot for the data. Do you detect a trend?

City Slug Pct Elevation Anaheim .480 160 Arlington .605 616 Atlanta .530 1050 Baltimore .505 130 Boston .505 20 f f f Denver .625 5277 f f f Seattle .550 350 San Francisco .510 63 St. Louis .570 465 Tampa .500 10 Toronto .535 566