(Chapter 7 Process Interruptions ) Galactica makes camera housings used in satellites. Galactica's process begins with a Computer Numerically Controlled (CNC) machine that drills into a block of metal to make the camera housing. The CNC machine requires a 30 minute setup time before the production of a batch of camera housings can commence. Each block requires 10 minutes of drilling on the CNC machine. Next, the batch of camera housings are chemically treated in a series of baths. There is unlimited capacity in the treating stage. Finally, a worker must manually attach the various buttons and components to the metal housing. The assembly takes 120 minutes per housing per worker, no setups, and Galactica has 6 workers trained to do this task. Assume unlimited demand. The process is shown below. Note there are buffers between the stages of the process. Drilling on CNC machine ===> Chemical Treatment====> Assembly With batch size of 30 housings, what is the average inventory of housings produced by the CNC machine? Group of answer choices 3 housings 7.5 housings 15 housings 30 housings