A process that is considered to be in control measures an ingredient in ounces. Below are the last $10$ samples $($each of size n $=5)$ taken. The population process standard deviation, s$,$ is $1\mathrm{.}36.$SAMPLES

$1$

$2$

$3$

$4$

$5$

$6$

$7$

$8$

$9$

$1010910912$

$91310$

$991011101111101010910$

$1210101010119810111281099$

$13810812$

$812$

$10128$

$98912$

$10$

a$)$ What is sx$?$

b$)$ If z $=3,$ what are the control limits for the mean chart? c$)$ What are the control limits for the range chart?

d$)$ Is the process in control?