Use the given information to find the number of degrees of freedom, the critical values x and xp , 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. Platelet Counts of Women 80% confidence; n = 30, s = 65.7. Click the icon to view the table of Chi-Square critical values. df = (Type a whole number.) x2 =0 (Round to three decimal places as needed.) XR = 0 (Round to three decimal places as needed.) The confidence interval estimate of o is