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i. Suppose the linear demand curve for shirts slopes downward and that consumers buy 500 shirts per year when the price is $30 and 1,000 shirts per year when the price is $25. Compared to the prices of $30 and $25, what can you say about the marginal valuation that consumers place on the 300th shirt, the 700th shirt, and the 1,200th shirt they might buy each year