We took two variables (number of cigarettes smoked per week and number of friends who smoke) to further examine their relationship, and came up with the equation to the trendline as the scatterplot below (y = 33.681x + 1.3326). Based on the above information, please answer the following questions: (4) Based on what you see in this scatterplot, determine which is the independent variable and which is the dependent variable, and explain the purpose of this regression analysis.