A marketing manager is studying the relationship between the sales and various marketing expenditures to determine the most successful techniques in the company's marketing mix. Analysis of the data produced the following multivariate regression output (in thousands $$): Unstandardized coefficients B St. Error Sig. (Constant) 800.2 108.633 0.415 TV advertising expenditures 0.22 0.996 0.000 Print advertising expenditures -0.15 9.828 0.000 Promotional expenditures 2.7 3.609 0.001 Social media marketing expenditures 0.17 0.554 0.031 R=0.61 1. Write down the regression equation. What seems to be the effect of each independent variable on the dependent variable? Based on this analysis, what is the most successful technique in the company's marketing mix? How much will $1 increase in expenditures for this technique affect sales? 2. How strong is the relationship between the variables? What is the explanatory power of the model? How can you interpret this