Problem 4

Problem 4. A company wants to test the effectiveness of their product advertising. It provides different marketing strategies in 10 regions. The following table contains advertising expenses [x in millions of dollars) and the number of sales [y in millions of units}. x | o |o.5 1 |1.5| 2 25 3 3.5 4 4.5 y |37.5 | 33.4 38.6I 39 |41.a 44.3 45.5 46.6 43.2 [a] Fit the linear regression model by least squares. [b] Calculate R2 for this model. [cl Estimate 0'2 for this model