Consider a multiple regression equation predicting life expectancy in a random sample of 35 countries.X1is per capita GDP andX2is country's homicide rate (per 100,000). Suppose the regression equation is Y = a + .5(X1) .08(X2). How should we interpret a?

a. It is the predicted life expectancy value when a country has a GDP of 0 and a homicide rate of 0.

b. It is the predicted life expectancy value for a country with an averagelevel GDP and an average homicide rate.

c. It is the partial correlation between GDP and homicide rate.