Question $1.(30$ points$)$

A police station in City D has instituted a quality$-$improvement program that makes extensive use of SPC

charts. It wants to monitor the response times for emergency calls to make sure they stay around nine

minutes on average. The administration staff randomly times six emergency calls each month during a $7$

month period and collects the following data. Clearly show all the procedures leading to your answers.

Month Response Times $($mins$)$

$19766106$

$2997875$

$359101067$

$41411991015$

$5129121087$

$6101059911$

$7766897$

$1)$ Develop a mean control chart and evaluate whether the emergency response process is in

control. $(15$ points$)$

$2)$ Develop an R$-$chart and evaluate whether the emergency response process is in control. $(15$

points$)$