The formula to calculate the Total Cost (TC) is:
\[ \text{TC} = \text{PBF} \times \text{TBF} \]
Where:
Let's say the price per board foot (PBF) is $5 and the total board feet (TBF) is 100. Using the formula:
\[ \text{TC} = 5 \times 100 = 500 \]
So, the total cost of the lumber is $500.