Final answer:
The percent markup for the surfboard that Ross purchased for $200 and sold for $320 is 60%.
Step-by-step explanation:
Ross buys and sells surfboards. If he purchases a used surfboard for $200 and sells it for $320, the percent markup is calculated based on the cost price (the price he bought it for). First, you find the absolute markup by subtracting the cost price from the selling price. So, the markup is $320 - $200 = $120. To find the percent markup, you divide the absolute markup by the cost price and then multiply by 100 to get the percentage. So, the percent markup is ($120 / $200) x 100 = 60%.