To determine how long an employee must work to make $80 at a rate of $20 per hour, we can set up the proportion based on the relation of money earned to hours worked.
The correct proportion representing this scenario is:
\[ \frac{20}{1} = \frac{80}{x} \]
This can also be rearranged to represent it as:
\[ 20x = 80 \]
However, from the options provided, the closest representation of this in fractional notation is:
\[ \frac{20}{x} = \frac{80}{1} \]
Thus, you would look for the option that resembles \( \frac{20}{x} = \frac{80}{1} \), or the equivalent form presented above.
Therefore, the correct option from your responses is: 80 over 1 is equal to 20 over x.