Final answer:
The nominal size of 1 1/2 x 5 1/2 lumber is 1.5 inches thick by 5.5 inches wide. The ratio of the lumber is 1.5:5.5. When placed 16.0 inches apart, the distance in centimeters is 40.64 centimeters.
Step-by-step explanation:
The nominal size of 1 1/2 x 5 1/2 lumber refers to the size of the lumber before it is planed down. In the case of 1 1/2 x 5 1/2, the actual size of the lumber is 1.5 inches thick by 5.5 inches wide.
Ratio: The ratio of 1 1/2 x 5 1/2 can be written as 1.5:5.5. This means that for every 1.5 inches in thickness, the lumber is 5.5 inches wide.
Conversion: To convert inches to centimeters, we can use the conversion factor of 2.54 cm per inch. So, if the lumber is placed 16.0 inches apart, the distance in centimeters would be 16.0 inches x 2.54 cm/inch = 40.64 centimeters.