To write the proportion describing the relationship between the required height-to-length ratio and the ramp's height-to-length ratio for a wheelchair ramp, we start with the required ratio of height to length.
The required ratio is 1:12, which can be represented as the fraction:
\[ \frac{1}{12} \]
For a ramp with a height of 2.2 feet and a length of 26.4 feet, the height-to-length ratio is:
\[ \frac{2.2}{26.4} \]
Now we can set up a proportion using these two ratios:
\[ \frac{1}{12} = \frac{2.2}{26.4} \]
Thus, the proportion showing the relationship between the required height-to-length ratio and the ramp's height-to-length ratio is:
\[ \frac{1}{12} = \frac{2.2}{26.4} \]