The formula is |(estimated - exact ÷ exact) x 100|
((15.375 - 15.125) / 15.125) x 100 = 1.652892562
You might want to round that number a 'lil
Part 2: She got 14.875 b/c with the equation there are no negative percentages, so that means that since 15.375 - 15.125 = 0.25, than 15.125-0.25 = what she got.