The May 1, 2007, College Retirement Equity Fund (CREF) prospectus lists the following sample returns on $1 invested in two of the fund's accounts, per year.5
Equity Index Account ($): 1.636, 1.441, 0.973, 1.055, 1.400
Money Market Account ($): 1.169, 1.273, 0.976, 0.998, 0.953
Assuming these data are random samples, is there statistical evidence that one account is better than the other?