The reported unemployment is 5.5% of the population. What measurement scale is used to measure unemployment?

The correct answer is letter "C": Interval or ratio.

Explanation:

Interval measurements refer to providing an object of study a value based on a scale between two values. Those values could fall below zero. Ratio measurements represent a specific numerical amount usually expressed in fractions or percentages and cannot fall below zero.

Then, if the unemployment is 5.5% of the population is has been measured as a ratio.