Continuing the previous problem, the managers of this manufacturing process have implemented more stringent quality control procedures to reduce the variability of the light bulbs' defective rate. The file P20_25.xlsx contains the proportion of defective light bulbs found in each of 30 samples (again, with a common size of 100 units) taken after the implementation of the new quality control procedures. Use these sample observations to assess the impact of the managers' corrective actions. Support your conclusions with a p chart.