Final answer:
The percent markup based on cost is calculated by subtracting the cost from the selling price, dividing this by the cost, and then multiplying by 100.
Therefore, the percent markup when the store owner sells the microwave for $275, which was bought for $200, is 37.5%.
Step-by-step explanation:
If a store owner buys a microwave for $200 and sells it for $275, the percent markup based on cost can be calculated as follows:
- First, find the difference between the selling price and the cost price: $275 - $200 = $75.
- Then, divide the difference by the cost price: $75 / $200 = 0.375.
- Finally, to find the percentage, multiply the result by 100: 0.375 × 100 = 37.5%.
Therefore, the percent markup based on cost is 37.5%.