5.6. The data here shown are for 100% inspection of lots of malleable castings for cracks by magnaflux. The lot size varies considerably, so a p chart is used instead of an np chart. By some care, one can use only four separate n’s. Make the control chart and comment.

Lot number Lot size n Nonconformities d Fraction nonconforming p 1 1138 143 0.126 2 600 30 0.050 3 700 298 0.426 4 500 70 0.140 5 750 141 0.188 6 600 26 0.043 7 750 130 0.173 8 775 141 0.182 9 750 17 0.023 10 850 66 0.078 11 775 126 0.163 12 750 20 0.027 13 675 100 0.148 14 1395 32 0.023 15 116 16 0.138 16 750 116 0.155 17 780 132 0.169 18 1400 40 0.029 19 424 50 0.118 20 384 16 0.042 21 286 22 0.077 22 1000 52 0.052 23 360 51 0.142 24 1100 38 0.035 17608 1873 0.1064