6. An international business uses a simple linear regression model to estimate the relationship between the number of advertisements X and the sales amount Y. According to the monthly data of the business from January to October, 111, the average value of the 10 sales is 130, while the variation is 1748. As for the average number of 10 advertisements, it is 14. Additionally, the covariance between the sales amount Y and the number of advertisements X is 316. Also, the regression equation estimated using the classical least squares method (OLS) is: Y = 60 + 5X.
Please answer: (25 %)