Find the linear relationship between price (P) and the quantity demanded (Q), i.e. find the straight-line demand equation, in relation to the following sales and demand data: Selling price of $200 = sales of 1,000 units per month Selling price of $220 = sales of 950 units per month. REQUIRED: (a) Use this equation to predict the quantity demanded per month if the selling price is $300 (b) Using the price equation in (a) and assuming the variable cost per unit is $100, calculate the optimum price and output. (c) Calculate the maximum contribution