The chemical benzene is highly toxic to humans. However, it is used in the manufacture of many medicine dyes, leather, and coverings. Government regulations dictate that for any production process involving benzene, the water in the output of the process must not exceed 7950 parts per million (ppm). It is known from historical data that the standard deviation σ is 100 ppm. Required:
a. What is the probability that the sample average in this experiment would exceed the government limit if the population mean is equal to the limit?
b. Is an observed = 7960 in this experiment firm evidence that the population mean for the process exceeds the government limit?