If the inputs are 8.4 V and 1.2 V in Figure 19-2(a) the Output voltage equals _____ A) 9.6 V B) -9.6 V C) 10.08 V D) 7.2 V If the inputs are 4.1 V, -0.7 V and 3.1 V in Figure 19-2(b), the output voltage equals _____. A) -6.5 V B) 13 V C) 6.5 V D) -13 V What change causes the circuit in Figure 19-2(b) to output the average of the three input voltages? A) Change to a different type of op-amp. B) Change the feedback resistor to 10 k Ohm. C) Change the input resistors to 3.3 k Ohm. D) Change the feedback resistor to 3.3 k Ohm. If the inputs are -7.1 V and 12 V in Figure 19-2(a), what is the output voltage? voltage? A) -19.1 V B) 19.1 V C) -4.9 V D) 4.9 V