Quarters are currently minted with weights normally distributed and having a standard deviation of 0.067. new equipment is being tested in an attempt to improve quality by reducing variation. a simple random sample of 20 quarters is obtained from those manufactured with the new equipment, and this sample has a standard deviation of 0.042. use a 0.05 significance level to test the claim that quarters manufactured with the new equipment have weights with a standard deviation less than 0.067. does the new equipment appear to be effective in reducing the variation of weights?