Mercury is a heavy metal that can cause severe health problems in even small concentrations. Fish and shellfish efficiently concentrate mercury into their flesh, so it is important to monitor seafood for its mercury content. An extensive study conducted in 1980 concluded that the mean mercury level in oysters from the White Bear estuary was 0.021 parts per million (ppm) with a population standard deviation of 0.032 ppm. In 2012, a sample of 47 oysters from the same estuary exhibited a sample mean mercury concentration of 0.017 ppm. Can you conclude that the 2012 mercury concentration is lower than in 1980