document.write( "Question 1189495: Which of the following exam scores is better relative to other students enrolled in the course? • A psychology exam grade of 85; the mean grade for the psychology exam is 92 with a standard deviation of 3.5 • An economics exam grade of 67; the mean grade for the economics exam is 79 with a standard deviation of 8 • A chemistry exam grade of 62; the mean grade for the chemistry exam is 62 with a standard deviation of 5 \n" ); document.write( "

Algebra.Com's Answer #820867 by ikleyn(52814) $\"\"$ $\"About$

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\n" ); document.write( "Which of the following exam scores is better relative to other students enrolled in the course?
\n" ); document.write( "(a) A psychology exam grade of 85; the mean grade for the psychology exam is 92 with a standard deviation of 3.5;
\n" ); document.write( "(b) An economics exam grade of 67; the mean grade for the economics exam is 79 with a standard deviation of 8;
\n" ); document.write( "(c) A chemistry exam grade of 62; the mean grade for the chemistry exam is 62 with a standard deviation of 5.
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document.write( "For each exam/grade you should calculate its z-score; then compare three z-score to determine which one is higher.\r\n" );
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document.write( "Use the formula for z-score\r\n" );
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document.write( "    Z = \r\n" );
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document.write( "where\r\n" );
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document.write( "Z	=	standard score\r\n" );
document.write( "x	=	observed value\r\n" );
document.write( "mu	=	mean of the sample\r\n" );
document.write( "sigma	=	standard deviation of the sample\r\n" );
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document.write( "Use this formula separately for each case.\r\n" );
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document.write( "(a)   =  = -2;\r\n" );
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document.write( "(b)   =  = -1.5;\r\n" );
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document.write( "(c)   =  =  0.0.\r\n" );
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document.write( "So, the score  is highest.  It means that that the exam score is better (is the best) for this exam (c).    \r\n" );
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document.write( "The three Z-scores are in this order   <  < .\r\n" );
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