When two goods are perfect substitutes, their indifference curves are straight lines

A decrease in real GDP can

A) shift money demand to the right and increase the interest rate. B) shift money demand to the left and increase the interest rate. C) shift money demand to the right and decrease the interest rate. D) shift money demand to the left and decrease the interest rate.

Even though insignificant explanatory variables can raise the adjusted R2 of a demand function, one should not interpret their effects on the regression when

a. testing marketing hypotheses about the determinants of demand b. analyzing inventory relative to capacity requirements c. forecasting unit sales for operations planning d. sales revenue reaches its peak e. planning for capital budgets