Differential equation of the NPN transistor configured as a voltage divider
Marie --- a emttier resistor and a collector resistor MAY approximately set the gain, if

beta is high


Vce &gt;&gt; 0 volts (perhaps 1-10 volts, but well out of saturation)

Examine the maths, perturb (introduce tiny changes) the voltages, and extract WHY
Rc/Re
is a good predictor.