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Z-scores: Standardized Data ValuesMeasures the distance of a number from the mean in units of the standard deviation

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z-score corresponding to y

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Exam 1: y1 = 88, s1 = 6; exam 1 score: 91 Exam 2: y2 = 88, s2 = 10; exam 2 score: 92Which score is better?

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Comparing SAT and ACT ScoresSAT Math: Eleanors score 680SAT mean =500 sd=100ACT Math: Geralds score 27ACT mean=18 sd=6Eleanors z-score: z=(680-500)/100=1.8Geralds z-score: z=(27-18)/6=1.5Eleanors score is better.

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Z-scores add to zero

Student/Institutional Support to Athletic Depts For the 8 Public ACC Schools: 2008 ($ millions)SchoolSupporty - ybarZ-scoreClemson4.5-3.713-0.8806FSU7.5-0.7125-0.1690GaTech6.0-2.213-0.5248Maryland17.18.88752.1082NCSU5.5-2.713-0.6434UNC6.4-1.813-0.4299UVA11.93.68750.8747VaTech6.8-1.413-0.3351Mean=8.2125, s=4.216Sum = 0Sum = 0

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In 2007-08 the mean tuition at 4-yr public colleges/universities in the U.S. was $6185 with a standard deviation of $1804. In NC the mean tuition was $4320. What is NCs z-score?1.03-1.032.391865-1865

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End of Section 2.3