Groundwater contamination of wells. Methyl tert-butyl ether (MTBE) is a lead fue...

Groundwater contamination of wells. Methyl tert-butyl ether (MTBE) is a lead fuel additive that can contaminate drinking water through leaking underground storage tanks at gasoline stations. A study published in Environmental Science & Technology (Jan. 2005) investigated the risk of exposure to MTBE through drinking water in New Hampshire. Data were collected for a sample of 223 public and private New Hampshire wells. Suppose environmental regulations stipulate that only half the wells in the state should have MTBE levels that exceed .5 micrograms per liter. This implies that the median MTBE level should be less than .5. Do the data collected by the researchers (saved in the MTBE file) provide evidence to indicate that the median level of MTBE in New Hampshire groundwater wells is less than .5 micrograms per liter? Use the accompanying MINITAB printout to answer the question.