The analyst in Exercise 11 fits the model with the four predictor variables. The regression output shows:

Response Variable: Spending R2 = 84.92% Adjusted R2 = 84.85%

s = 48.45 with 908 - 5 = 903 degrees of freedom Variable Coeff SE(Coeff) t-ratio P-value Intercept -3.738e + 00 1.564e + 01 -0.239 0.811 Past Spending 1.063e - 01 4.203e - 03 25.292 60.0001 Income 1.902e - 03 3.392e - 04 5.606 60.0001 Networth 2.900e - 05 3.815e - 05 0.760 0.447 Age 6.065e - 01 7.631e - 01 0.795 0.427

a) How many observations were used in the regression?

b) What might you do next?

c) Is it clear that Income is more important to predicting Spending than Networth? Explain.