A worker is exposed to the following airborne concentrations of ethylbenzene: 8:00 – 10:00 125 ppm 10:15 – 12:15 88 ppm 12:45 – 3:15 112 ppm 3:30 – 5:00 70 ppm What is the 8-hour TWA exposure for the employee (calculate the exposure)? Does it exceed the OSHA PEL?