Refer to the Following Data for Jobs Waiting to Be

Short Answer

Refer to the following data for jobs waiting to be processed at a single work center (jobs are shown in order of arrival):
$$\begin{array} { l c c } \text { Job } & \begin{array} { c } \text { Processing Time } \\( \text { days } )\end{array} & \begin{array} { c } \text { Due Date } \\\text { (days from now) }\end{array} \\\hline \mathrm { A } & 2 & 2 \\\mathrm {~B} & 5 & 6 \\\mathrm { C } & 6 & 10 \\\mathrm { D } & 3 & 4 \\\mathrm { E } & 4 & 8\end{array}$$ What is the average completion time for the shortest processing time priority rule? Average job tardiness? Average number of jobs at the center?