To find out how long it will take Stacy to paint the entire room, we can set up a proportion based on the rate at which she paints.
Stacy can paint \( \frac{3}{4} \) of the bedroom in 3 hours.
To find her rate of work, we can calculate how long it takes her to paint 1 full bedroom:
\[ \text{If } \frac{3}{4} \text{ room takes 3 hours, then 1 room takes } \frac{3}{\frac{3}{4}} \text{ hours.} \]
To divide by a fraction, we multiply by the reciprocal: \[ \frac{3}{\frac{3}{4}} = 3 \times \frac{4}{3} = 4 \text{ hours.} \]
So, it will take Stacy 4 hours to paint the entire room.
Therefore, the correct response is:
4 hours