Using the following data determine the equation of the regression model. How many independent variables are there?

Question:

Using the following data determine the equation of the regression model. How many independent variables are there? Comment on the meaning of these regression coefficients.
Predictor .. Coefficient
Constant ... 121.62
x1 ...... -.174
x2 ...... 6.02
x3 .... .00026
x4 .... .0041