There are dozens of personality tests available on the World Wide Web. One test, scored on a scale of 0 to 200, is designed to give an indication of how "personable" the test taker is, with higher scores indicating more "personability."Suppose that scores on this test have a mean of 99 and a standard deviation of 21. Complete the following statements about the distribution of scores on this personality test.

(a) According to Chebyshev's theorem, at least?56%, 75%, 84%, 89%

of the scores lie between 67.5 and 130.5.

(b) According to Chebyshev's theorem, at least?56%, 75%, 84%, 89%

of the scores lie between 57 and 141.

(c) Suppose that the distribution is bell-shaped. According to the empirical rule, approximately?68%, 75%, 95%, 99.7%

of the scores lie between 57 and 141.

(d) Suppose that the distribution is bell-shaped. According to the empirical rule, approximately 68% of the scores lie between

and

.