Bill bought a shirt for $35.80 plus he paid an additional 7% in sales tax. What was the final cost? Show your proportion or equation set-up.

To find the final cost you multiply 35.80 x. 07 and you get 2.506 but since its money you round it to $2.51. $2.51 is your sales tax and now you need to add it to the cost of the shirt so 35.80+2.51 = $38.31