To solve the problem using the scale provided, we can set up a proportion.
The scale states that 1 inch in the drawing corresponds to 4 feet in actual size.
Let \( x \) be the length of the room in the drawing in inches.
We can set up the following proportion:
\[ \frac{x \text{ inches}}{20 \text{ feet}} = \frac{1 \text{ inch}}{4 \text{ feet}} \]
Now, cross-multiply to find \( x \):
\[ x \cdot 4 = 20 \cdot 1 \]
This simplifies to:
\[ 4x = 20 \]
Now, divide both sides by 4:
\[ x = \frac{20}{4} = 5 \]
Thus, the length of the room in the drawing is 5 inches.