Yоu wоrk аt Andy’s Burger Bаrn, а burger chain. Yоur boss, Andy, has asked you to determine the relationship between advertising and sales using regression analysis. The table below contains data on monthly sales revenues (Sales) and expenditures on advertising (Advert). Both Sales and Advert are measured in thousands of dollars. Calculate the estimate of ß1. Round your answer to the second decimal place.