Four Samples of 100 Each Were Taken from an Assembly

Multiple Choice

Four samples of 100 each were taken from an assembly line, with the following results: Using the historical average as the central line of the chart, which one of the following is the limits for an attributes control chart with z = 2?

$$\begin{array} { | l | l | } \hline \text { Sample } & \text { Number } \\\text { Number } & \text { Defective } \\\hline 1 & 6 \\2 & 12 \\\hline 3 & 2 \\\hline\end{array}$$

A) UCL < 0.1 and LCL < 0.03
B) UCL < 0.1 and LCL > 0.03
C) UCL > 0.1 and LCL < 0.03
D) UCL > 0.1 and LCL > 0.03