Assume you are working in a data analysis team at a company and you have access to volume of sales data over time. Last month, your company increased its YouTube ads, and the manager of the company thinks that these ads were very successful. One of your team members suggested a regression analysis to see if because of the increased ads, the volume of sales increased last month. What do you think about this suggestion? Assume that you decide to perform the regression analysis, what are the independent and dependent variables in your regression? If you run the regression and you find out that the slope coefficient of the regression is positive, does this necessarily mean your manager was right about the effect of new ads?