Create a "magic" square (4 columns wide x 4 rows deep) using the 12 through 27. The sum of each column should be 78, each row should be 78 and the diagonals as well.

2 answers

Take any 4x4 magic square and add 11 to each cell.

Many 4x4 magic squares are available, not to mention the famous Albrecht Dürer magic square, which actually appears on one of his paintings:
http://mathworld.wolfram.com/DuerersMagicSquare.html

Here are some examples:
http://www.halexandria.org/dward090.htm

Here's the recipe to make your own 4x4 magic squares:
http://www.dr-mikes-math-games-for-kids.com/even-order-magic-square-recipe.html
I'm mmm