The graph of a function is shown below.

At which of the labeled -values is least? ? x1 x2 x3 x4 x5 x6 greatest? ? x1 x2 x3 x4 x5 x6 least? ? x1 x2 x3 x4 x5 x6 greatest? ? x1 x2 x3 x4 x5 x6