Problem E

Just an Average Sum

Faisal chooses four numbers. When each number is added to the mean (average) of the other three, the following sums are obtained: \(25\), \(37\), \(43\), and \(51\).

Determine the mean of the four numbers Faisal chose.

Extra Problem: Can you interpret the following picture puzzle? You may need to research the meanings of some mathematical symbols used in the puzzle.