The analyst in the Dorben Company wishes to measure the percentage of downtime in the drop hammer section of the forge shop. The superintendent estimated the downtime to be about 30 percent. The desired results, using a work sampling study, are to be within ±5 percent of p with a level of significance of 0.95. The analyst decides to take 300 random readings a day for three weeks. Develop a p chart for p = 0.30 and subsample size N = 300. Explain the use of this p chart.