We can represent the relative prices of the two inputs by drawing an isocost line in X,Y space. An isocost line plots the combinations of the inputs that can be purchased at current relative prices for a given level of expenditure. The slope of an isocost line is given by the ratio ...
She took it back to the store, but the clerk in the store said they wouldn't take it back, and they wouldn't give her money back, because she bought it on sale. So the only thing she could do was to buy a new one. I'm sure Mary is more careful when she buys things now, a...