a multiple regression analysis based on a data set that consists of 30 observations yielded the following estimated demand equation: Q=120 - 1.1P + 0.04I + .90A where P is the price, I is Income, and A is advertising. If price is equal to $1000, income is equal to $20,000, and advertising expenditures are equal to %500, then the predicted quantity dmenaded (Q) is what?