Final answer:
The nominal size of 3/4 x 11 1/4 lumber is 3/4 inch thick and 11 1/4 inches wide.
Step-by-step explanation:
The nominal size of 3/4 x 11 1/4 lumber refers to its rough-sawn dimensions before it is planed and sanded. In this case, the lumber is 3/4 inch thick and 11 1/4 inches wide. The length of the lumber is not specified, so it could vary. The nominal size is often larger than the actual size due to the planing and sanding process.