The estimated demand for a good is Q = 4,800 - 16P - 0.65M - 1.5Pr where Q is the quantity demanded of the good, P is the price of the good, M is income, and Pr is the price of related good R.
This good and good R are
a. Complements since the coefficient on M is negative.
b. Substitutes since the coefficient on M is negative.
c. Complements since the coefficient on Pr is negative.
d. Substitutes since the coefficient on Pr is negative.
e. None of the above.