As part of a larger study into the role of the hippocampus in memory, Fortin et al. (2004) devised a test that required rats to choose between two odors, one of which had previously been presented to them as the first in a series of odors. To validate their procedure, the researchers tested whether normal rats are able to remember and choose the odor previously presented. By chance, the rats should score only 50% on the test. But if they are able to remember, they should score better than 50% Seven normal rats were taken through the protocol, and their scores on the memory test were on average 68.4% with a standard deviation of 7.1% Do the rats show the ability to perform this task at levels better than that expected by chance? State all necessary assumptions.