Chapter 13.2, Problem 26E

In anthropological studies, an important characteristic of fossils is cranial capacity. Frequently skulls are at least partially decomposed, so it is necessary to use other characteristics to obtain information about cranial capacity. One measure that has been used is the length of the lambda-opisthion chord. The article “Vertesszollos and the Presapiens Theory” (American Journal of Physical Anthropology [1971]) reported the accompanying data for n = 7 Homo erectus fossils.

Suppose that from previous evidence, anthropologists had believed that for each 1-mm increase in chord length, cranial capacity would be expected to increase by 20 cm 3. Do the data given here strongly contradict prior belief?