I need the FMV of metlife on 11/16/2005 for an estate tax return.  The
directions state I should use the mean which is in between the High
and low market values for the date of death.

According to finance.google.com
MetLife opened at $49.87 USD that day and closed at $50.33 (thereby
giving you an average price of (49.87+50.33)/2= $50.10 USD.

However, more details area available at
finance.yahoo.com has:

Date	        Open	High	Low	Close	Volume	     Adj Close*
16-Nov-05	49.87	50.35	49.76	50.33	1,570,700	50.33

In this case we have the true high and low of the day not just the
open and close prices....

$49.76 + $50.35 /2 = $50.055 (or $50.06).

So, based on your definition of FMV I would use $50.055.

http://ca.finance.yahoo.com/q/hp?s=MET&a=10&b=16&c=2005&d=10&e=16&f=2005&g=d