Public health and safety officials have classified the Zika virus as a hazardous threat to pregnant women in Brazil. A study based in Rio found the virus to be more active near a body of water that was found to be polluted. A study of 20 water samples found an average chemical waste of 208 g per mile with a standard deviation of 10.18 g. A button hyperlink to the SALT program that reads: Use SALT. (a) What are the degrees of freedom for this study? 19 Correct: Your answer is correct. (b) Find the 95% confidence interval (in g per mile) for this study. (Use a table or technology. Round your answers to three decimal places.) Incorrect: Your answer is incorrect. x \pm (t critical value) s n , Incorrect: Your answer is incorrect. x \pm (t critical value) s n g per mile