Final answer:
The percent markup based on the selling price of the TV is 25.93%, calculated by dividing the dollar markup ($87.50) by the selling price ($337.50) and then multiplying by 100.
Step-by-step explanation:
When calculating the percent markup based on the selling price, you must compare the profit to the selling price rather than the cost. The seller's markup was 35% of the $250 cost, meaning the markup in dollars was 0.35 × $250 = $87.50. Hence, the TV was sold for $250 + $87.50 = $337.50.
We can now calculate the percent markup based on the selling price by dividing the markup dollars by the selling price and then converting that to a percentage.
Markup based on the selling price = ($87.50 / $337.50) × 100 = 25.93% (rounded to two decimal places).
Therefore, the percent markup based on the selling price is 25.93%.