You are the Filipino analyst hired by the multinational company to study the sales data of its more than 75 stores worldwide. You used regression analysis to predict $ sales (y) by using $ advertising...

You are the Filipino analyst hired by the multinational company to study the sales data of its more than 75 stores worldwide. You used regression analysis to predict $ sales (y) by using $ advertising (x₁) and $ salary of sales representatives (x₂) across all the branches. You obtained the following regression function: y = 7800 + 8.5x₁-1.6x₂

If the advertising budgets of one of the branches of the corporation increased by 10% and the salary of sales representatives decreased by 20%, then its predicted sales will?