A study was made of the relationship between retail auto sales (dependent variable) and the level of aggregate wages and salaries in the economy (independent variable). One would expect a higher level of wages and salaries to lead to an increase in auto sales. The fitted regression line is listed below. is the quarterly retail auto sales from the first quarter of 1979 to the first quarter of 2008 in billions of dollars, and W is the quarterly wages for the same period in billions of dollars.

S = 2.582 + 0.0398 W
t (2.33) (40.1)
R² = 0.93

Explain the meaning of each coefficient in the equation