What is the calculated TWA? What would you tell plant management in terms of exposure to acetone and compliance with the PEL?

1) You are an industrial hygienist conducting personal sampling on a worker who is overseeing a production process involving use of acetone (Note: The Occupational Safety and Health Administration has established a Permissible Exposure Limit of 1000 parts per million (ppm) of acetone). You are able to measure the following exposures:

700 ppm for 3 hours

1300 ppm for 2 hours

900 ppm for 3 hours

What is the calculated TWA? What would you tell plant management in terms of exposure to acetone and compliance with the PEL?