Finding the percentage increase or decrease: Advanced The price of a notebook has dropped to $\$ 3.50$ today. Yesterday's price was $\$ 3.75$. Find the percentage decrease. Round your answer to the nearest tenth of a percent.

Step 1 ：Understand the problem: We are asked to find the percentage decrease in the price of a notebook from yesterday to today.

Step 2 ：Calculate the decrease in price: The decrease in price is the original price (yesterday's price) minus the new price (today's price). So, the decrease in price = \(3.75 - 3.50 = 0.25\)

Step 3 ：Calculate the percentage decrease: The percentage decrease is the decrease in price divided by the original price, then multiplied by 100 to convert it to a percentage. So, the percentage decrease = \((0.25 / 3.75) * 100\)

Step 4 ：Perform the calculation: = \((0.25 / 3.75) * 100 = 0.06666666666666667 * 100 = 6.666666666666667\)

Step 5 ：Round to the nearest tenth of a percent: = \(6.7\%\)

Step 6 ：Check the result: The price of the notebook decreased by $0.25, which is 6.7% of the original price of $3.75. Therefore, the result meets the requirements of the problem.

Step 7 ：\(\boxed{6.7\%}\)