4. What steps do you perform to apply a 15% discount to a product in a customer's invoice.

1. In the discount boxes below the invoice table, choose Discount percent and 15.
2. In the discount boxes below the invoice table, choose Discount amount, calculate the dollar amount for the 15% discount and fill it in the second box with the discount as a negative number.
3. Create a service for discounts, add it to the invoice, calculate the dollar amount for the 15% discount and fill it in the Amount cell as a positive number.
4. Create a service for discounts, add it to the invoice, calculate the dollar amount for the 15% discount and fill it in the Amount cell as a negative number.