So my question is how to calculate the voltage gain for the amplifier? and the ratio of the voltage amplitudes? Is their a formula or just by reading the graph..
I don't know if the input is 5mV RMS, 5mV peak or 5mV p-p.
You can calculate the gain if you calculate the value of the internal emitter resistance of the transistor and the parallel combination of the 2k collector resistor with the 10k load resistance.