  The expected range of a sample of n+1 normally distributed variables is known
to be related to the mean width of a regular n-simplex. We show that the
expected maximum mu_n of a sample of n half-normally distributed variables is
related to the mean width of a regular n-crosspolytope. Both of these relations
have mean square counterparts. An expression for mu_5 is found and is believed
to be new.
