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 150 and 200 is 50 (200 - 150 = 50).

Next, we need to find the average of the two numbers. The average of 150 and 200 is (150 + 200) / 2 = 175.

Now, we can calculate the percentage difference by dividing the absolute difference by the average and multiplying by 100. So, the percentage difference between 150 and 200 is (50 / 175) x 100 = 28.57%.

This means that the second number (200) is 28.57% higher than the first number (150). Alternatively, we could say that the first number (150) is 22.22% lower than the second number (200).