Final answer:
The total restaurant bill is calculated by adding the sales tax to the cost of the meal, then adding the tip. Sales tax is found by multiplying the meal cost by the tax rate, and the tip is calculated by multiplying the meal cost by the tip percentage.
Step-by-step explanation:
Calculating the total bill at a restaurant requires us to consider not just the base cost of the meal, but also any sales tax and tips. To compute the total charge, you first add the sales tax to the base price of the meal by converting the tax rate from a percentage to a decimal and multiplying it by the cost. For example, if the sales tax rate is 6% (which is 0.06 when expressed as a decimal), and the cost of the meal is $47.50, you would calculate the sales tax as $47.50 × 0.06, which equals $2.85. This amount is then added to the original $47.50 to account for the tax. The next step is to calculate the tip. If you decide to leave an 18% tip, which is a common amount, you convert that percentage to a decimal (0.18) and multiply it by the base cost of the meal then add that to your total. For an $18 tip on a $72 meal, the calculation would be $72 × 0.18, which equals $12.96. Adding this to the original and tax gives the final total that will be paid at the register if using a credit card.