EXPLANATION
Let's analyze the statement:
DVD purchase price = $12.00
Customer sale price = +50% purchase price = 1.5*12 = $18.00
Adding the tax cost to the sale price:
[tex]\text{Sale price + tax cost=\$18.00 + \$18}.00\cdot0.07=18.00+1.26=19.26\text{ }[/tex]Hence, the customer's total cost for the DVD was of $19.26