HOMEWORK-REGRESSION

Part 1- You are again given the same 10 observations that you were provided with in the Correlation problem .However, you are now asked to derive the regression line,y= a+bX for the data below. After you have calculated the regression equation, explain to me how you could use it.

Part 2- Calculating the Standard Error of the Estimate-S_{y.x .} You will be using the same summation data that you used to derive the equation of the regression line,Y=a +bX,in Regression ( Part I ) After you have calculated the Standard Error of the Estimate,Sy.x,tell me what the number you have obtained means.

Part 3- Calculating a Prediction Interval for a particular value of X

In this problem ,you will be using the results of Part I and Part II, which were Y =a+bX and S_y.x ,to compute a prediction interval value for a particular value of X. Use X=25 as the particular value of X.

DATA

X (Independent Variable) Y (Dependent variable)

Month Advertising Expenditure (in Millions of $) Sales Revenue (in Millions of $)

March 20 30

April 40 60

May 20 40

June 30 60

July 10 30

August 10 40

September 20 40

October 20 50

November 20 30

December 30 70