Twelve samples, each containing five parts, were taken from a process that produces steel rods at Emmanual Kodzi's factory. The length of each rod in the samples was determined. The results were tabulated

and sample means and ranges were computed. The results were:

For the given data, the $\frac{?}{\text{b}\text{a}\text{r}}(\stackrel{}{x})=9\mathrm{.}2003$ inches $($round your response to four decimal places$).$

Based on the sampling done, the control limits for $3-$sigma $\stackrel{}{x}$ chart are:

Upper Control Limit $(UC{L}_{\frac{?}{\text{b}\text{a}\text{r}}()})=$ inches $($round your response to four decimal places$).$

WHAT IS UCL? AND LCL$?$

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