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 147 and 136 is 11 (147 - 136 = 11).

Next, we need to find the average of the two numbers. The average of 147 and 136 is (147 + 136) / 2 = 141.5.

Now, we can calculate the percentage difference by dividing the absolute difference by the average and multiplying by 100. So, the percentage difference between 147 and 136 is (11 / 141.5) x 100 = 7.78%.

This means that the difference between 147 and 136 is 7.78% of the average of the two numbers.