hi. ^_^ we recently did this experiment on measuring the actual resistances of resistors. every time, the actual resistance was less than the resistance on the label, except for the resistors arranged in parallel. the theoretical value for 100 ohm and 220 ohm resistors is 67.5 ohms, but our reading is 68 ohms. in the series arrangement the value was supposed to be 320 ohms, but we got just 316 ohms. when we measured individual resistances, the measured value was also always less than the theoretical one. does anyone know the explanation why the resistors in parallel don't follow the trend? thanks so much..