3.28 Four different designs for a digital computer circuit are being studied to compare the amount of noise present. The following data have been obtained: Circuit Design Noise Observed a. Is the same amount of noise present for all four designs? Use a = 0.05. b. Analyze the residuals from this experiment. Are the analysis of variance assumptions satisfied? c. Which circuit design would you select for use? Low noise is best. 1 19 20 19 30 8 2 80 61 73 56 80 3 47 26 25 35 50 4 95 46 83 78 97