Instruction 18-5
the Maker of a Packaged Candy Wants to Evaluate

Instruction 18-5
The maker of a packaged candy wants to evaluate the quality of her production process.On each of 16 consecutive days,she samples 600 bags of candy and determines the number in each day's sample that she considers to be of poor quality.The data that she developed follow.
$\begin{array}{ccc}&Number&Proportion\\Day&Poor&Poor\\\hline1 & 33 & 0.0550000 \\2 & 29 & 0.0483333 \\3 & 31 & 0.0516667 \\4 & 32 & 0.0533333 \\5 & 43 & 0.0716667 \\6 & 45 & 0.0750000 \\7 & 46 & 0.0766667 \\8 & 48 & 0.0800000 \\9 & 48 & 0.0800000 \\10 & 46 & 0.0766667 \\11 & 28 & 0.0466667 \\12 & 32 & 0.0533333 \\13 & 28 & 0.0466667 \\14 & 32 & 0.0533333 \\15 & 31 & 0.0516667 \\16 & 24 & 0.0400000\end{array}$
-Referring to Instruction 18-5,a p control chart is to be constructed for these data.The centre line for the chart should be located at ________.