A nationwide test taken by high school sophomores and juniors has three sections, each scored on a scale of 20 to 80. In a recent year, the national mean score for the writing section was 51.7 , with a standard deviation of 10.9. Based on this information, complete the following statements about the distribution of the scores on the writing section for the recent year.
(a) According to Chebyshev's theorem, at least ?56%75%84%89% of the scores lie between 24.45 and 78.95.
(b) According to Chebyshev's theorem, at least ?56%75%84%89% of the scores lie between 29.9 and 73.5.
(c) Suppose that the distribution is bell-shaped. According to the empirical rule, approximately ?68%75%95%99.7% of the scores lie between 29.9 and 73.5.
(d) Suppose that the distribution is bell-shaped. According to the empirical rule, approximately 99.7% of the scores lie between and.