A Nevada Bank Keeps Track of Errors from 20 Clerks

Essay

A Nevada Bank keeps track of errors from 20 clerks.Each sample has 100 records.They want to construct a P-chart to track the proportion of errors in each sample.The table below shows the number of errors per sample.(Use z = 3 for control limit calculations.)​​ $\begin{array}{|cc|cc|cc|}\hline \text { Sample } & \text { Errors } & \text { Sample } & \text { Errors } & \text { Sample } & \text { Errors } \\\hline \mathbf{1} & 6 & \mathbf{8} & 6 & \mathbf{1 5} & 5 \\\mathbf{2} & 5 & 9 & 4 & 16 & 1 \\\mathbf{3} & 3 & \mathbf{1 0} & 9 & 17 & 2 \\\mathbf{4} & 4 & \mathbf{1 1} & 2 & \mathbf{1 8} & 6 \\\mathbf{5} & 5 & \mathbf{1 2} & 6 & \mathbf{1 9} & 2 \\\mathbf{6} & 4 & \mathbf{1 3} & 5 & \mathbf{2 0} & 7 \\7 & 2 & \mathbf{1 4} & 4 & \text { TOTAL } & \mathbf{8 8} \\\hline\end{array}$ ​SHOW YOUR CALCULATIONS
a. Determine . $\bar{P}$
b. Determine σ_P.
c. Determine the 3-sigma UCL and LCL.Does the process appear to be in statistical control?