Which of these describes a quantitative observation?
a. an observation of the phenomenon itself
b. an observation of the relative size of something
c. an observation of an effect the phenomenon has
d. an observation that has a number associated with it

Paleontologists have found plant fossils deep within the layers of the north polar region. these leaf fossils have been labeled as to the rock layers they were found in, with the lower numbers being layers close to the earth's surface and higher numbers representing deeper layers. according to the numbers of these four leaf fossils, what might you infer?