Use the given information to find the number of degrees of freedom, the critical values x and x , and the confidence interval estimate of o. It is reasonable to assume that a simple random sample has been selected from a population with a normal distribution. Nicotine in menthol cigarettes 80% confidence; n = 24, s = 0.27 mg. Click the icon to view the table of Chi-Square critical values. if = (Type a whole number.) xz = (Round to three decimal places as needed.) XR =(Round to three decimal places as needed.) The confidence interval estimate of o is | mg