In the real world many variables will impact on the behavior of a given variable. For example, in a business situation there is more than one variable that impacts on the profits one makes such as the current supply of product available and the current demand for the product. Creating a regression model that accounts for only one of these would not result in a very good predictor of profit. What is multiple regression? Is there any limit to the number of explanatory variables that could be used to predict or estimate the value of a single response variable? Find a real-world variable related to your degree or career field and discuss all the variables that would be needed to provide an accurate estimate of its behavior. Are they all equally important in predicting or estimating the value of the response variable? Why or why not?