3. David is a salesman for a local Ford dealership. He is paid a percent of the profit the dealership makes on each car. If the profit is under
$800, the commission is 25%. If the profit is at least $800 and less
than $1,000, the commission rate is 27.5% of the profit. If the profit
is $1,000 or more, the rate is 30% of the profit. Find the difference
between the commission paid if David sells a car for a $1,000 profit
and the commission paid if he sells a car for a $799 profit?