Q$4\mathrm{.}7($Atlas Inc.$)$ Atlas Inc. is a toy bicycle manufacturing company producing a $5-$inch small version of the bike that Lance Armstrong rode to

win his first Tour de France. The assembly line at Atlas Inc. consists of $7$ workstations, each performing a single step. Stations and

processing times are summarized here:

Step $1(30$ sec$.)$: The plastic tube for the frame is cut to size.

Step $2(20$ sec$.)$: The tube is put together.

Step $3(35sec.)$: The frame is glued together.

Step $4(25$ sec$.)$: The frame is cleaned.

Step $5(30$ sec$.)$: Paint is sprayed onto the frame.

Step $6(45sec.$