Checked with a multimeter, voltages are what they should be. I dont know why the Serial monitor is showing them as averaged... The diagram is real complex, not sure how I'd post it. It has three batteries, a load cell, amplifier, and LEDs. But the battery and loadcell are on totally different circuits.
Well the output impedance of the signals (if too high) you are reading could be a factor, and if not that then your sketch is mangling the values before sending them out to the serial monitor.
So without wiring diagram and sketch code help will be just guessing.