To find the percentage difference between two numbers, we first need to calculate the absolute difference between them. In this case, the absolute difference between 176 and 220 is 44 (220 - 176 = 44).

Next, we need to find the average of the two numbers. The average of 176 and 220 is (176 + 220) / 2 = 198.

Now, we can calculate the percentage difference by dividing the absolute difference by the average and multiplying by 100. So, the percentage difference between 176 and 220 is (44 / 198) x 100 = 22.22%.

This means that the second number (220) is 22.22% higher than the first number (176).