Six samples of five observations each have been taken of $80$ kg concrete slabs

produced by a machine and the results is showed below.

a$)$ Please choose the suitable control charts to test whether or not the process is in

control.

b$)$ Based on the data in part a$),$ the specification for the concrete slabs is $78$kg to $81$kg$,$ is

the specification being met, calculate both cp and cpk$?$ Using the formulation $=$

$$

$$

$\%($n is sample size and $$ refers to tables in Week $8$ slide$)$ to estimate the

standard deviation from average range.

Sample

$123456$

$79\mathrm{.}280\mathrm{.}579\mathrm{.}678\mathrm{.}980\mathrm{.}579\mathrm{.}7$

$78\mathrm{.}878\mathrm{.}779\mathrm{.}479\mathrm{.}479\mathrm{.}680\mathrm{.}6$

$80\mathrm{.}081\mathrm{.}080\mathrm{.}479\mathrm{.}780\mathrm{.}480\mathrm{.}5$

$78\mathrm{.}480\mathrm{.}480\mathrm{.}379\mathrm{.}480\mathrm{.}880\mathrm{.}0$

$81\mathrm{.}080\mathrm{.}180\mathrm{.}880\mathrm{.}678\mathrm{.}881\mathrm{.}1$