Nine consecutive integers are placed in the nine squares of a 3x3 grid. If every column, every row, and every diagonal adds up to the same number n and the middle number is 8 what is n?

Can you arrange the numbers from 1 to 9 on a tic tac toe board in a manner that the numbers in each row, column and diagonal adds up to 15. Remember that you have to use all the 9 numbers and thus you cannot repeat.

Fill the missing number,
numbers are 1 to 9,
numbers in each row add up to the right,
numbers in each column add up to the bottom,
numbers in each diagonal add up to the right?