A sales boy gave a change of 68 instead of 72. Calculate the percentage error?

To calculate the percentage error, we need to find the difference between the expected change and the given change, and then divide that difference by the expected change.

The expected change is 72, and the given change is 68.

Difference = Expected change - Given change = 72 - 68 = 4

Percentage error = (Difference / Expected change) * 100
= (4 / 72) * 100
= 5.56%

Therefore, the percentage error is 5.56%.