A manufacturing company wants to investigate which of three possible assembly methods for an electric motor is the most efficient. Since there is a fair amount of variability in the expertise of the workforce, it is decided to take workers as a blocking variable in the experiment. A random selection of b = 10 workers are trained in each of the k = 3 assembly methods, and then after a suitable amount of practice, they are timed under each method. The resulting data set is given in DS 11.2.6. Which assembly method is quickest? Use a computer package to obtain a graphical presentation of the data set and to help you with the analysis.