I have a question regarding a circuit that would take the average of 4 inputs and have an output as the average of the 4 inputs using an Op-Amp. First the equation would be Vo = (V1+V2+v3+v4)/4, so assuming all positive inputs you rewrite that as Vo = (1/4)V1...(1/4)V4. I figured you set the feedback resistor to 40k, then the input resistors would be 160k in series with the input voltage source. The input voltages would be tied to the positive terminal of the opamp and the negative side would be grounded. Obviously something is wrong, can I get some direction on where to go from here?