Squirt's assembly unit has decided to use a p$-$Chart with an alpha risk of $5\%$

to monitor the proportion of defective copper wires produced by their production process. The quality control manager randomly samples $150$

copper wires at $12$

successively selected time periods and counts the number of defective copper wires in the sample.

Table

Sample Defects

$18$

$210$

$313$

$412$

$57$

$611$

$710$

$89$

$912$

$1014$

$1110$

$1212$

Control Chart

Step $1$ of $8$: What is the Center Line of the control chart? Round your answer to three decimal places.