$($a$)$ Calculate the average range of all samples. $($Keep one decimal place.$)$

$($b$)$ Calculate all sample means and the mean of all sample means. $($Keep one decimal place.$)$

$($c$)$ Calculate the upper and lower control limits for R chart. $($Please round your answers to two decimal places.$)$

$($d$)$ Calculate upper and lower x$-$bar chart control limits$.($Please round your answers to two decimal places.$)$

$($e$)$ Is this process in control?