Final answer:
Mountain Dew's price elasticity of demand at 4.4 signifies a high sensitivity of demand in response to price changes, indicating it has a high price elasticity of demand, and likely many substitutes.
Step-by-step explanation:
The price elasticity of demand measures how sensitive the quantity demanded of a good is to a change in its price. When the price elasticity of demand for a product is high (greater than 1), it means that consumers' demand for the product is sensitive to price changes. In the case of Mountain Dew, with a price elasticity of demand at 4.4, this indicates that Mountain Dew has a high price elasticity of demand. Therefore, if the price of Mountain Dew increases, the quantity demanded would decrease significantly, and vice versa. This high elasticity suggests that there are likely many substitutes available for Mountain Dew, as consumers can easily switch to other beverages in response to price changes.