# Selftest Problems And Solutions

ST4.1 Demand and Supply Curves. The following relations describe demand and supply conditions in the lumber/forest products industry:

where Q is quantity measured in thousands of board feet (one square foot of lumber, one inch thick) and P is price in dollars.

A. Set up a table or spreadsheet to illustrate the effect of price (P), on the quantity supplied (QS), quantity demanded (QD), and the resulting surplus (+) or shortage (-) as represented by the difference between the quantity demanded and the quantity supplied at various price levels. Calculate the value for each respective variable based on a range for P from \$1.00 to \$3.50 in increments of 10tf (i.e., \$1.00, \$1.10, \$1.20, . . . \$3.50).

B. Using price (P) on the vertical or Y-axis and quantity (Q) on the horizontal or X-axis, plot the demand and supply curves for the lumber/forest products industry over the range of prices indicated previously.

### ST4.1 Solution

A. A table or spreadsheet that illustrates the effect of price (P) on the quantity supplied (QS), quantity demanded (QD), and the resulting surplus (+) or shortage (-) as represented by the difference between the quantity demanded and the quantity supplied at various price levels is as follows:

+1 0 