I am working on a spreadsheet with SUMPRODUCT results that have set parameters.

The problem I am to solve says:
A factory builds TVs, stereos, and speakers. There are five types of parts:
chassis, picture tubes, speaker cones, power supplies, and electronics
units. A TV earns $75 gross profit, a stereo earns $50, and a speaker cone
earns $35. There are 450 chassis, 250 picture tubes, 800 speaker cones, 450
power supplies, and 600 electronics units.

I have created SUMPRODUCT formulas to determine how many TVs, stereos, and
speakers will produce maximum profit. I need to set parameters for the
formulas so that for each part, the result does not exceed the number of such
parts available. The site, http://www.solver.com/stepbystep2.htm, mentions
solver dialogs, but I cannot locate these. Pleaae help - the problem is
supposed to be solved before midnight Mountain Time this Sunday, October 5!