So, I'm going along, studying for my exams, and get to my Business Stats notes. We're covering Simple and Multiple Regression for our exam, and I was able to get a general idea about how simple regression works, given certain values such as SSR, SSE, and SST in the actual problems. Once I had moved onto the multiple regression problems, however, I realized that I was unable to take data points and actually find these values, since we had never actually been shown in class how to compute them. I will post what I have available for a sample problem that I was hoping to work out below.
Quarter;_______Sales, Millions $ (Dependent Variable)____Car Sales, Millions______Money Supply Index_______Oil Price $/barrel (Independent variables)
2008 Q2____________35.16_____________________________40.4____________________2.29____________________18.83
2008 Q3____________32.3______________________________38.0____________________2.32____________________19.75
2008 Q4____________32.78_____________________________35.6____________________2.32____________________18.53
2009 Q1____________30.91_____________________________35.6____________________2.33____________________17.61
2009 Q2____________30.5______________________________36.7____________________2.36____________________17.95
2009 Q3____________28.8______________________________35.9____________________2.36____________________15.84
2009 Q4____________30.22_____________________________36.9____________________2.36____________________14.28
2010 Q1____________29.52_____________________________37.9____________________2.38____________________13.02
2010 Q2____________30.04_____________________________37.2____________________2.37____________________15.89
2010 Q3____________31.17_____________________________39.0____________________2.39____________________16.91
2010 Q4____________29.17_____________________________39.3____________________2.40____________________16.29
2011 Q1____________31.07_____________________________41.9____________________2.42____________________17
2011 Q2____________30.33_____________________________40.0____________________2.43____________________17.93
2011 Q3____________31.42_____________________________43.2____________________2.44____________________16.98
a. What is the regression equation? Report R[sup:2eu5fc1t]2[/sup:2eu5fc1t] and adjusted R[sup:2eu5fc1t]2[/sup:2eu5fc1t].
b. Predict the sales for the fourth quarter of 2011 using the regression equation. The car sales were $42.7 million, the MSI as 2.46 and the oil price was $17.51/barrel.
c. It is claimed that oil price does not affect demand for tools. Conduct a t test with a = 5%.
d. Remove the oil price variable from the model and repeat the regression. Report the new R[sup:2eu5fc1t]2[/sup:2eu5fc1t] and adjusted R[sup:2eu5fc1t]2[/sup:2eu5fc1t].
While it would be exceptionally beneficial to have a run-through of all of the questions with this example, I believe I can figure out the most of this problem if shown how to compute SSR and SSE, since if I have those, I can get SST. The book I have came with a CD that has excel templates for each chapter, but I don't know how to use it. I entered in the information I was given into the cells, and the most I got from it was that the SSE may be 13451.17. Even though I have the number, I'd like to know how it was found so I can do it by myself come exam time. Thank you in advance for any help I receive on this problem.
Quarter;_______Sales, Millions $ (Dependent Variable)____Car Sales, Millions______Money Supply Index_______Oil Price $/barrel (Independent variables)
2008 Q2____________35.16_____________________________40.4____________________2.29____________________18.83
2008 Q3____________32.3______________________________38.0____________________2.32____________________19.75
2008 Q4____________32.78_____________________________35.6____________________2.32____________________18.53
2009 Q1____________30.91_____________________________35.6____________________2.33____________________17.61
2009 Q2____________30.5______________________________36.7____________________2.36____________________17.95
2009 Q3____________28.8______________________________35.9____________________2.36____________________15.84
2009 Q4____________30.22_____________________________36.9____________________2.36____________________14.28
2010 Q1____________29.52_____________________________37.9____________________2.38____________________13.02
2010 Q2____________30.04_____________________________37.2____________________2.37____________________15.89
2010 Q3____________31.17_____________________________39.0____________________2.39____________________16.91
2010 Q4____________29.17_____________________________39.3____________________2.40____________________16.29
2011 Q1____________31.07_____________________________41.9____________________2.42____________________17
2011 Q2____________30.33_____________________________40.0____________________2.43____________________17.93
2011 Q3____________31.42_____________________________43.2____________________2.44____________________16.98
a. What is the regression equation? Report R[sup:2eu5fc1t]2[/sup:2eu5fc1t] and adjusted R[sup:2eu5fc1t]2[/sup:2eu5fc1t].
b. Predict the sales for the fourth quarter of 2011 using the regression equation. The car sales were $42.7 million, the MSI as 2.46 and the oil price was $17.51/barrel.
c. It is claimed that oil price does not affect demand for tools. Conduct a t test with a = 5%.
d. Remove the oil price variable from the model and repeat the regression. Report the new R[sup:2eu5fc1t]2[/sup:2eu5fc1t] and adjusted R[sup:2eu5fc1t]2[/sup:2eu5fc1t].
While it would be exceptionally beneficial to have a run-through of all of the questions with this example, I believe I can figure out the most of this problem if shown how to compute SSR and SSE, since if I have those, I can get SST. The book I have came with a CD that has excel templates for each chapter, but I don't know how to use it. I entered in the information I was given into the cells, and the most I got from it was that the SSE may be 13451.17. Even though I have the number, I'd like to know how it was found so I can do it by myself come exam time. Thank you in advance for any help I receive on this problem.