In order to determine whether or not the sales volume of a company (Y in millions of dollars) is related to advertising expenditures (X1 in millions of dollars) and the number of salespeople (X2), data were gathered for 10 years. Part of the regression results is shown below.
Analysis of Variance (incomplete)
Source of Degrees Sum of Mean
Variation of Freedom Squares Square F
Regression 2 321.11
Coefficient Standard Error
Constant 7.0174 1.8972
X1 8.6233 2.3968
X2 0.0858 0.1845
a. Use the above results and write the regression equation that can be used to predict sales.
b. Estimate the sales volume for an advertising expenditure of 3.5 million dollars and 45 salespeople. Give your answer in dollars.
c. At ïÂ?¡ = 0.05, test to determine if the fitted equation developed in part a represents a significant relationship between the independent variables and the dependent variable.
Please show the steps for the calculations, I want to compare them against my numbers
Step by step method for regression analysis is discussed here. Regression coefficients, coefficient of determination, scatter diagram and significance of regression model are explained in the solution.