Final answer:
The heights of a species of tree represent the ratio level of measurement because they have a true zero point and allow for mathematical operations such as multiplication and division, enabling the comparison of proportions between heights.
Step-by-step explanation:
The heights in inches of a sample of a species of tree two years after being planted represent ratio level of measurement. The ratio level of measurement is characterized by the presence of an absolute zero point, meaning that you can have a value of zero height which indicates the absence of the tree height. Furthermore, ratio data allows for the full range of mathematical operations: it is possible to say that one tree is twice as tall as another.
For instance, if the height of one tree is 50 inches and another is 25 inches, it can be concluded that the first tree is twice as tall as the second. Furthermore, the heights can be compared, added, subtracted, multiplied, or divided, which are all properties of ratio data.