Crystal received her SAT score from her counselor. She scored two standard deviations above the mean. What does this indicated about Crystal's score?

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chickflik999 eNotes educator| Certified Educator

To know what this says about her score, we first have to understand a couple of statistical terms.  First of all, mean in the average score.  Standard deviations are set marks that are based around the mean.  68% of the scores occur within one deviation of the mean, 95% of scores occur within two deviations from the mean, and 99.7% of scores occur within three standard deviations from the mean.  Since Crystal's score was two deviations above the mean, we know that she had a higher score than 95% of the people who take the SAT's.  This means that her score is in the top 5%.