Scaling Entire Drawing

[Rich Shepard <rshepard appl-ecosys com>]

  I'm brand new to Dia (using 0.96.1), and didn't realize that the rulers
are in centimeters despite my setting the page size to US Letter. So I ended
up drawing the ER diagram much too large.

  When I selected all objects I could not find a menu choice that would
allow me to scale the entire drawing so it fits on a single sheet of paper.
Neither the tutorial nor the 8-year-old manual tells me how to scale the
whole thing.

  How can I do this?

TIA,

Rich