In an effort to determine if advertisement expenditures lead to greater revenue from online sales of surfboards, a firm examined 32 weeks of data. The regression model was Y = revenue (in thousand of dollars), X₁ = total expenditures in web advertising (in thousand of dollars), X₂ = total expenditures in print advertising (in thousand of dollars), X₃ = average surfboard volume for the week (liters). The table below presents the estimated coefficients.

a) Write the fitted regression model.
b) Interpret the web ad expenditures coefficient.
c) Interpret the surfboard volume coefficient.

Transcribed Image Text:

Predictor Intercept X₁ X₂ X3 Coefficient 6.79 3.97 1.48 -2.85