Gas central heating and air conditioning have been found to have significant positive impacts on the ln-sale price. If the analyst is interested in investigating if gas central heating and air conditioning together would further impact on the ln-sale price, discuss how to proceed with your regression analysis

Q1 Introduce an interactive variable and how to create it.

Q2 Run the regression with existing independent variables and the interactive independent variable.

Q3 Implications on the interpretations of the marginal gas and air conditioning effects