Tyler Apiaries sells bees and beekeeping supplies. Bees $($including a queen$)$ are shipped in special packages according to weight. The target weight of a package is $1\mathrm{.}5$ kg $.$ Historically, Tyler's

shipments have weighed on average $1\mathrm{.}5$ kg $,$ with a standard deviation of $0\mathrm{.}18$ kg $.$

a$.$ The lower and upper tolerance limits are $1\mathrm{.}1$ kg and $1\mathrm{.}9$ kg $,$ respectively.

The process capability ratio is

$($Enter your response rounded to three decimal places.$)$