The production of a nationally marketed detergent results incertain workers receiving prolonged exposures to a Bacillussubtilis enzyme. Nineteen workers were tested to determine theeffects of those exposures, if any, on various respiratoryfunctions. One such function, airflow rate, is measured bycomputing the ratio of a person’s forced expiratory volume (FEV) tohis or her vital capacity (VC). (Vital capacity is the maximumvolume of air a person can exhale after taking as deep a breath aspossible; FEV is the maximum volume of air a person exhale in onesecond.) In persons with no lung dysfunction, the “norm” for FEV/VCratios is 0.80. Assume that the FEV/VC ratios are known to benormally distributed. For the 19 workers in the study, the meanFEV/VC ratio was 0.766 with standard deviation 0.0859. a. Based onyour result, is it believable that exposure to Bacillus subtilisenzyme has no effect on the FEV/VC ratio? Please compute thep-value for the test in two different ways: (i) assuming σ = 0.09and (ii) assuming σ is unknown. b. Based on this data, is itbelievable that σ = 0.09 ? Conduct a hypothesis test to answer thisquestion.
