In: Statistics and Probability
The following set of data shows how the advertising budget affects its sales (both in millions of dollars):
Advertising. Sales
| 12.5 | 148 | 
| 3.7 | 55 | 
| 21.6 | 338 | 
| 60 | 994 | 
| 37.6 | 541 | 
| 6.1 | 89 | 
| 16.8 | 126 | 
| 41.2 | 379 | 
Develop the equation of the simple regression line to predict sales from advertising expenditures using these data. You will need to:
-Calculate the intercept and slope of the linear regression formula that relates the advertising to sales.
-Calculate the value of R-squared.
-Predict the sales, in millions of dollars, if the advertising budget is 50, 70, 90 million dollars.
-How strong is the correlation? What is your confidence in the numbers you calculated?