4-6 A company owns several manufacturing facilities. Suppose employees have a suspicion that they are being over-exposed to high carbon monoxide (CO). The company takes 30 readings to test the carbon...

Extracted text: 4-6 A company owns several manufacturing facilities. Suppose employees have a suspicion that they are being over-exposed to high carbon monoxide (CO). The company takes 30 readings to test the carbon monoxide level over a several week span and find a sample mean of 55 ppm. For these manufacturing facilities o = 12 ppm. 4) Construct a 99% confidence interval for the population mean level of carbon monoxide at their facilities. 5) The OSHA PEL (permissible exposure limit) for CO is 50 ppm. OSHA standards prohibit worker exposure to more than 50 parts of CO gas per million parts of air averaged during an 8-hour time period. Does your interval suggest that the workers are being over exposed to carbon monoxide? Explain. 6) Suppose another sample of 30 readings are taken resulting in a sample mean level of CO of 60 ppm. Create another interval for the population mean, µ. Based on this sample, are the workers being over exposed to carbon monoxide? Explain your reasoning.