The file P3_65.XLS contains the measured weight (in ounces) of a particular brand of ready-to-eat breakfast cereal placed in each of 500 randomly selected boxes by one of five different filling machine operators. Quality assurance personnel at this company are interested in determining how well these five operators are performing their assigned task of consistently placing 15 ounces of cereal in each box. 

a. Employ descriptive graphs and summary measures to ascertain whether some or all of these operators are consistently missing the target weight of 15 ounces per box.

b. If you were charged with selecting the “Outstanding Employee of the Month” from this set of filling machine operators, which operator would you select based on the given data? Defend your choice.