Pedro Martinez, who retired from Major League Baseball in 2012, had a stellar career, helping the Boston Red Sox to their first World Series title in 86 years in 2004. The next year he became a free agent and the New York Mets picked him up for $53 million for 4 years. Even after the move to New York, Martinez had his own fans. Possibly, he attracted more fans to the ballpark when he pitched at home, helping to justify his multimillion dollar contract. Was there really a “Pedro effect” in attendance? We have data for the Mets home games of the 2005 season. The regression has the following predictors:

Here’s the regression.

a) All of these predictors are of a special kind. What are they called?
b) What is the interpretation of the coefficient for Pedro Start?
c) If we’re primarily interested in Pedro’s effect on attendance, why is it important to have the other variables in the model?
d) Could Pedro’s agent claim, based on this regression, that his man attracts more fans to the ballpark? What statistics should he cite?