Final answer:
To compare 3 feet to 31 inches, convert 3 feet to 36 inches (as there are 12 inches in a foot) and then write the ratio, which simplifies to ⅔ as a fraction.
Step-by-step explanation:
To write the ratio of the first measurement to the second measurement in inches, we must ensure both measurements are in the same unit. Since 3 feet need to be compared to 31 inches, we first convert feet to inches. There are 12 inches in one foot, so 3 feet is equal to 3 × 12 inches, which is 36 inches. Now, both measurements are in inches, and we can write the ratio.
The ratio of the first measurement to the second measurement is therefore:
36 inches : 31 inches
As a simplified fraction, this ratio is:
⅔