It could be either, we need more info. How big are each? If it doesn't say, then it's a trick question. Throw Schrodinger's cat at it or something.
Answer
Find out the how much did each student recieve .
To prove
Let us assume that each student earned in the bake sell be x .
As given
Three students earned $48.76 at the bake sell.
The students split the earnings evenly i.e earning is divided into three equal parts .
Than the equation becomes

Solving the above
x = $16.25(approx)
Therefore the each student recieve $16.25(approx) .
Hence proved
No her estimate is to low because if you multiply 15.5 by 12 you get 186