Statistical monitoring of a quality characteristic uses both an $$ and an s chart. The charts are to be

based on the standard values M $=200$ and o $=10,$

with n $=4.$

a$.$ Find three$-$sigma control limits for the s chart.

b$.$ Find a center line and control limits for the I chart such that the probability of a type I error is $0\mathrm{.}05.$

$6\mathrm{.}29.$