A random sample of data has a mean of 60 and a variance of 16. a. Use Chebychev's theorem to determine the percent of observations between 52 and 68. b. If the data are mounded, use the empirical rule to find the approximate percent of observations between 52 and 68. a. Using Chebychev's theorem, the portion of the data which are between 52 and 68 is at least s %. 'Round to one decimal place as needed.)