4. In trying to evaluate the effectiveness in its advertising campaign, a rm compiled the following information: Calculate the regression equation of sales on advertising expenditure. Estimate the probable sales when advertisement expenditure is Rs.60 thousand. Year Advertisement expenditure Sales 2003 12 5.0 2004 15 5.6 2005 17 5.8 2006 23 7 .0 2007 24 7 .2 2008 3 8 8.8 2009 42 9 .2 2010 48 9 .5 8. A social scientist would like to analyse the relationship between educational attainment and salary. He collects the following sample data, where education refers to years of higher education and salary is the individuals annual salary (in $10005) Education 3 4 6 2 5 4 8 0 Salary 40 53 80 42 70 50 110 38 Find the estimating regression equation. What is the predicted salary for an in dividual who completed 7 years of higher education