Final answer:
The hat has been marked down by 25% from its original price of $36.00 to $27.00.
Step-by-step explanation:
Lisa finds that a hat has been marked down from its original price of $36.00 to $27.00. To calculate the percentage of the markdown, we first need to find the difference in price, which is the original price minus the marked down price. So, the difference in price is $36.00 - $27.00 = $9.00. Next, we calculate the markdown percentage by dividing the difference by the original price and then multiplying by 100 to convert it to a percentage. Therefore, the markdown percentage is ($9.00 ÷ $36.00) × 100, which equals 25%. Thus, the hat has been marked down by 25%.