If we have a demand curve which can be described by Pd= 72.33-1.76Q, and we have a starting price of $50, what happens to TR when the price falls to $40? Find whether MR is positive or negative and fully explain why. Now, for the same demand curve, what happens to MR when the price falls from $20 to $10? Is this consistent with what happened in the first instance, or not? Show this in Excel by graphing a TR curve.