Question 84320
Another way to think about this question is:
"What must Friday's balance be for the average daily balance of the account to be $500/"

You can set up the equation like this:

{{{(540+435.5+345.3+310+x)/5=500}}}
Where x is the Friday balance. Now just solve for x:
{{{(1630.8+x)/5=500}}}
{{{1630.8+x=2500}}}
{{{highlight(x=869.20)}}}
Good Luck,
tutor_paul@yahoo.com