Hello there! We are solving for the tax rate, so let's start off by subtracting both prices. 4.32 - 4.00 is 0.32. That's a 32 cent difference in the price. Now, let's divide that number by the original price to find the percentage. 0.32/4 is 0.08. Multiply that number by 100 and that is 8%. There. The sales tax rate is 8%.