Since the frozen dinner at the grocery store was bumped up by 40%, the new price would have been $3.08
Now, a customer wants to buy 4 frozen dinners, so multiply the price of one frozen dinner by 4.
$3.08 x 4 = $12.32
There is a 9% sales tax put up for the grocery store. You will want to multiply 9% (or .09) times the price of the 4 frozen dinners.
$12.32 x .09 ~ $1.11
Add the sales tax price to the price of the four frozen dinners.
$12.32 + $1.11 = $13.43
$13.43 will be the amount the customer will pay.
