Final answer:
The most appropriate level of measurement for people's age is ratio.
Step-by-step explanation:
The most appropriate level of measurement for people's age is ratio.
Ratio scale data has a 0 point and allows for the calculation of ratios. In the case of age, we can measure the differences between ages and calculate ratios, such as someone being twice as old as another person.
For example, if one person is 20 years old and another person is 40 years old, the ratio between their ages is 2:1.