ANSWER and EXPLANATION
A double number line is used to represent ratios.
To draw a double number line, follow the steps below:
Step 1: Draw two parallel horizontal lines
Step 2: Mark point 0 on the same spot on both lines
Step 3: Mark the number on the left side of the ratio (1) on the top line and the other number (4) on the bottom line such that they are at the same point.
Step 4: Use a dotted line to join them
Following these steps, we have: