math
posted by b .
The buying and selling commission schedule shown below is from a wellknown online discount brokerage firm.?
Taking into consideration the buying and selling commissions in the schedule find annual rate of interest earned by each investment?
Transaction Size Commission Rate
$0$2,500 $19+ 1.6% of principal
$2,501$6,000 $44 + 0.6% of principal
$6,001$22,000 $62 + 0.3% of principal
$22,001$50,000 $84 + 0.2% of principal
$50,001$500,000 $134 + 0.1% of principal
$500,001+ $234+ 0.08% of principal
An investor purchases 500 shares at $14.20 a share, holds the stock for 39 weeks, and then sells the stock for $16.84 a share.

What you have listed are investment commissions.
The total charge was in this case $7200 plus $62 + 21.30. That is 7283.39. The stock was sold for $16.84 a share, or $8420.00 There would be selling commission of %62 + 25.26 = 87.26
The net return on the buying and selling of the stock would be
8420.  7283.39  83.30  87.26 = 966.05
966.05 profit in 39 weeks on a purchase of 7283.39 is an annual percentage rate gain of 17.7%