Final answer:
A decrease in supply will increase total revenue if demand is price inelastic. This happens because the price increase from reduced supply does not significantly affect the quantity demanded, leading to increased revenue.
Step-by-step explanation:
An increase in total revenue in a market due to a decrease in supply is possible under certain conditions. To address the question: A decrease in supply (shift to the left) will increase total revenue in that market if?, the correct response is 1) demand is price inelastic.
When demand is price inelastic, consumers are less sensitive to price changes. This means that the quantity demanded does not decrease significantly when the price increases. Thus, if supply decreases, leading to an increase in the product's price, the total revenue will increase because the loss in sales volume is less than proportional to the price increase.