Final answer:
To find the total cost of the car with sales tax, multiply the car's price by the decimal form of the sales tax rate, round the sales tax to the nearest cent, and then add it to the original price; the total cost is $661.92.
Step-by-step explanation:
To calculate the total cost of a car with sales tax included, first you need to convert the sales tax rate to a decimal. In this case, a 6.25% sales tax rate is equivalent to 0.0625 in decimal form. Then, multiply the decimal rate by the car's listed price to find the amount of sales tax.
Amount of sales tax = $622.98 × 0.0625 = $38.93625
Now, round the sales tax to the nearest cent. The rounded sales tax is $38.94. Finally, add the rounded sales tax to the original price to find the total cost of the car.
Total cost = original price + sales tax = $622.98 + $38.94 = $661.92