Sample data set 11 7 10 8 4 6 10 6 11 7 (a) The sample standard deviation of the above data set is . Round answer to one decimal place. (b) Use the answer in part (a) to answer this question. The coefficient of variation is %. Do not write the % sign. (c) Use the answer in part (a) to answer this question. According to Chebychev's Theorem, at least % of the data lie between 5 and 11. Do not write the % sign.