Why are circuit results different from theorised?
Your measurements are impossible if the circuit shown is correct. 

12V / 20k&ohm; = 0.6mA. Therefore there cannot be 8.03mA going into the Base. However the slightly high Base-Emitter voltage suggests there is, so the '20k' resistor isn't 20k&ohm;. 

According to your measurements, the voltage at the Emitter should be 200&ohm;*(8.03mA+0.5114mA) = 1.708V, and voltage at the Base should be 1.708V+0.7745V = 2.48V. Therefore current through the 3.3k resistor should be 2.48V / 3.3k&ohm; = 0.75mA. (12V-2.48V)/(0.75mA+8.03mA) = 1.08k&ohm;. So the '20k' resistor is actually ~1.1k&ohm;.

Voltage at the Collector should be 12v-(10.83mV+1.708V) = 10.28V. 10.28V / 0.5114mA = 20.1k&ohm;. This suggests the '1.2k' resistor is actually 20k&ohm;. 

In other words, the 20k and 1.2k resistor are swapped around.