Improving SAT scores
The National Education Longitudinal Survey (NELS) tracks a nationally representative sample of U.S. students from eighth grade through high school and college. Research published in Chance (Winter 2001) examined the Standardized Admission Test (SAT) scores of 265 NELS students who paid a private tutor to help them improve their scores. The table below summarizes the changes in both the SAT-Mathematics and SAT-Verbal scores for these students.
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SAT-Math
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SAT-Verbal
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Mean change in score
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19
|
7
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Standard deviation of changes in score
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65
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49
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(a) Suppose one of the 265 students who paid a private tutor is selected at random. Give an interval that is likely to contain this student's change in the SAT-Math score.
(b) Repeat part a for the SAT-Verbal score.
(c) Suppose the selected student's score increased on one of the SAT tests by 140 points. Which test, the SAT-Math or SAT-Verbal, is the one most likely to have the 140-point increase? Explain.