3.11 Answers to the Marketing Plan questions
Is there a relationship between advertising budget and sales?
Tool: Multiple regression, look at F-statistic.
How strong is the relationship between advertising budget and sales?
Tool: \(R^2\) and RSE
Which media are associated with sales?
Tool: p-values for each predictor’s t-statistic. Explored further in chapter 6.
How large is the association between each medium and sales?
Tool: Confidence intervals on \(\hat{\beta_j}\)
How accurately can we predict future sales?
Tool:: Prediction intervals for individual response, confidence intervals for average response.
Is the relationship linear?
Tool: Residual Plots
Is there synergy among the advertising media?
Tool: Interaction terms and associated p-vales.