1.4Y. Here 325 is the repository of all relevant non-specified factors that affect demand for the product. P is the price of the good. The coefficient is negative in accordance with the law of demand. The related good may be either a complement or a substitute. If it is a complement, the coefficient of its price would be negative as in this example. If it is a substitute, the coefficient of its price would be positive. Income (Y), has a positive coefficient, indicating that the good is a normal good. If the coefficient were negative, the good would be an inferior good meaning that the demand for the good would fall as the consumer's income has increased. Specifying values for the non-price determinants, Prg = 4.00 and Y = 50, results in demand equation Q = 325 - P - 30(4) +1.4(50) or Q = 275 - P. If income were to increase to 55, the new demand equation would be Q = 282 - P. Graphically, this change in a non-price determinant of demand would be reflected in an outward shift of the demand function caused by a change in the x-intercept. Demand curve In economics the demand curve is the graphical representation of the relationship between the price and the quantity that consumers are willing to purchase. The curve shows how the price of a commodity or service changes as the quantity demanded increases. Every point on the curve is an amount of consumer demand and the corresponding market price. The graph shows the law of demand, which states that people will buy less of something if the price goes up and vice versa. According to Kotler, eight demand states are possible: Negative demand — Consumers dislike the product and may even pay to avoid it. Nonexistent demand — Consumers may be unaware of or uninterested in the product. Latent demand — Consumers may share a strong need that cannot be satisfied by an existing product. Declining demand — Consumers begin to buy the product less frequently or not at all. Irregular demand — Consumer purchases vary on a seasonal, monthly, weekly, daily, or even hourly basis. Full demand — Consumers are adequately buying all products put into the marketplace. Overfull demand — More consumers would like to buy the product than can be satisfied. Unwholesome demand — Consumers may be attracted to products that have undesirable social