A Quality Analyst wants to construct a control chart for determining whether four machines, all producing the same product, are under control with regard to a particular quality attribute. Accordingly, the analyst inspected $1,000$ units of output from each machine in random samples, with the following results:

Machine Total Defectives

#$123$

#$215$

#$329$

#$413$

What is the estimate of the process proportion of defectives based on the samples for these four machines?

Question $23$ options:

$\mathrm{.}04$

$\mathrm{.}06$

$\mathrm{.}02$

$\mathrm{.}01$

$\mathrm{.}08$