$\frac{?}{\text{b}\text{a}\text{r}}(\stackrel{}{x})=13\mathrm{.}801$ 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 $(UC{L}_{\stackrel{}{x}})=13\mathrm{.}8281$ inches $(round$ your response $to$ four decimal places$).$

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