If $\displaystyle a_k$ is a positive real number prove:
$\displaystyle (1/n)(a_1 + a_2 + a_3 .... + a_n) >= ({a_1}{a_2}{a_3}....{a_n})^{n^{-1}}$
Hello kevinlightmanThis is the AM-GM inequality. You'll find several proofs here: Inequality of arithmetic and geometric means - Wikipedia, the free encyclopedia
Grandad