A manufacturing company uses five identical assembly lines to construct one model of an electric toaster. All the toasters produced go to the same retail outlet. A recent complaint from this outlet indicates that there has been an increase in defective toasters in the past month. To determine the location of the problem, complete inspection of the output from each of the five assembly lines was done for a 22-day period. The number of defective toasters was recorded. The data are given below:
Use the ANOM procedure discussed at the end of Section 6.8 to determine whether the assembly lines differ relative to the number of defective toasters produced. Suggest ways in which the manufacturer could prevent complaints in the future.