To find the percentage difference between two numbers, we first need to find the absolute difference between them. In this case, the absolute difference between 216 and 192 is 24 (216 - 192 = 24).

Next, we need to find the average of the two numbers. The average of 216 and 192 is (216 + 192) / 2 = 204.

Now, we can calculate the percentage difference by dividing the absolute difference by the average and multiplying by 100. So, the percentage difference between 216 and 192 is (24 / 204) x 100 = 11.76%.

This means that the second number (192) is 11.76% less than the first number (216).