Final answer:
To find the rate of sales tax, subtract the cost of the book from the total amount paid, then divide the result by the cost of the textbook. Multiply the decimal by 100 to get the percentage.
Step-by-step explanation:
To find the rate of sales tax, we need to determine the amount of sales tax Matthew paid and then divide it by the cost of the textbook. We are given that Matthew paid a total of $113.94 for the book and sales tax, and the cost of the textbook is $108.00.
Therefore, the amount of sales tax is $113.94 - $108.00 = $5.94.
To find the rate of sales tax, we divide the amount of sales tax by the cost of the textbook: $5.94 / $108.00 = 0.055.
Finally, we convert the decimal to a percentage by multiplying by 100: 0.055 * 100 = 5.5%.