Ex. A group of research scientists collect 2000 water samplesfrom drinking water in Central Arizona. They test those samples fora certain chemical. The test isn’t 100% accurate. If the samplecontains the chemical, it will show a positive test result 93% ofthe time. If the sample does not contain the chemical, it gives anegative result 97% of the time. If 170 groundwater samples containchemicals, what is the probability the sample contains a chemicalif you have a positive test return for the sample
