13.27 Predicting restaurant revenue An Italian restaurant keeps monthly records of its total revenue, expenditure on advertising, prices of its own menu items, and the prices of its competitors’

menu items.

a. Specify notation and formulate a multiple regression equation for predicting the monthly revenue using the available data. Explain how to interpret the parameters in the equation.

b. State the null hypothesis that you would test if you want to analyze whether advertising is helpful, for the given prices of items in the restaurant’s own menu and the prices of its competitors’ menu items.

c. State the null hypothesis that you would test if you want to analyze whether at least one of the predictors has some effect on monthly revenue.