Which of the following statements about demand is true? The demand curve for a group of consumers in a market is simply the horizontal summation of each individual's demand. The single demand curve...

Extracted text: Which of the following statements about demand is true? The demand curve for a group of consumers in a market is simply the horizontal summation of each individual's demand. The single demand curve shows the quantity of a good that people will buy, allowing all factors (price, income, expected future prices, etc.) to vary. An increase in income will cause a person to move down and to the right along her demand curve.