Total before the sales rate:
$149.99+$119.95+$19.95 = $289.89
The 5.5% Sales tax is on the total, then :
the amount of the taxe is 5.5% x 289.89 ===> (5.5 x 289.89)/100 =15.944
The sales tax is to be added to the total, that is 289.89 + 15.944 =$305.834
