Answer:
..$5000 in sales: commission = (5000*5)/100= $250
$15,000 in subsequent sales: commission = (15,000*6.5)/100=$975
he sold for $23538, he already received commission 250+975=$1225
he receives 7% for sales above 20,000
28538-20000=$8538
he receives 7% = (8538*7)/100=$597.66
total commissions: 250+975+597.66=$1822.66
Explanation: