A production manager at a Contour Manufacturing plant has inspected the number of defective plastic molds in five random samples of $15$ observations each. Following are the number of defective molds found in each sample:A production manager at a Contour Manufacturing plant has inspected the number of defective plastic molds in five random samples of $15$ observations each. Following are the number of defective molds found in each sample: Sample Number of Defects Number of Observations in Sample $13302030313040305130$ Total $5150$ Construct a $3-$sigma control chart $($z $=3)$ with this information.