The last two would be your answer :)
<em><u>The equation can be used to find the actual length of Gregory's room is:</u></em>

<em><u>Solution:</u></em>
Given that,
The scale that he uses is:
1 cm : 4 feet
On this drawing, the room is 3 cm long
Let "x" be the actual length of room
Therefore,
1 cm : 4 feet
3 cm : "x" feet
This forms a proportion. Therefore,

Therefore, Option C is correct
Given that,
Rob chose A as the correct answer. Which is,

But option A is wrong
So, Rob made a mistake in measuring the equivalent ratio, it should be 
Over positive three and down 1. Hope it helps.
Answer:
x < 1 or x > 6
Step-by-step explanation: