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 192 and 77 is 115 (192 - 77 = 115).

Next, we need to find the average of the two numbers. The average of 192 and 77 is (192 + 77) / 2 = 134.5.

Now, we can calculate the percentage difference by dividing the absolute difference by the average and multiplying by 100. So, the percentage difference between 192 and 77 is (115 / 134.5) x 100 = 85.4%.

Therefore, the percentage difference between 192 and 77 is 85.4%. This means that the two numbers are quite different from each other, with one being significantly larger than the other.