Suppose your manager presents you with the following information about machines that could be used for a job, and wants your recommendation on which one to choose. The specification width is $\mathrm{.}48$ mm$.$ In this instance, you can narrow the set of choices, but you probably wouldn$$t make a recommendation without an additional piece of information. $($Round your answers to $3$ decimal places.$)$

Machine Cost per

Unit $($$$)$ Standard Deviation

$($mm$)$

A $13\mathrm{.}074$

B $12\mathrm{.}060$

C $20\mathrm{.}055$

D $10\mathrm{.}063$