If a consumer has a limited budget and is deciding between two products, how does the concept of marginal utility guide their purchasing decision when prices vary?

Marginal utility is the additional satisfaction or benefit a consumer gets from consuming one more unit of a product. When a person has a limited budget and is choosing between two products, they compare the marginal utility of each product to its price. For example, if a consumer is deciding between a pizza and a salad, they will consider how much happiness each additional slice of pizza or each bowl of salad brings them. If the pizza gives them more satisfaction per dollar spent than the salad, they are likely to choose the pizza. This way, consumers aim to maximize their happiness within their budget by selecting the product that offers the best value for their money.