document.write( "Question 265376: What are the probabilities that a student will receive an A, B, C, D, and F in a class? (using standard grading scale: A=90-100, B=80-89, C=70-79, D=60-69, F=0-59)?\r
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Algebra.Com's Answer #195186 by stanbon(75887)\"\" \"About 
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What are the probabilities that a student will receive an A, B, C, D, and F in a class? (using standard grading scale: A=90-100, B=80-89, C=70-79, D=60-69, F=0-59)?
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\n" ); document.write( "If you assume a normal distribution proceed as follows:
\n" ); document.write( "The range from 0 to 100 is 6 sigma
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\n" ); document.write( "If 6*sigma = 100
\n" ); document.write( "sigma = 100/6 = 16.67
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\n" ); document.write( "If you put the mean of the distribution at 70,
\n" ); document.write( "z(79) = (79-70)/16.67 = 0.5399
\n" ); document.write( "z(70) = (70-70)/16.67 = 0
\n" ); document.write( "P(70< x < 79) = P(0< z < 0.5399) = 0.2054 = 20.54% (percent that get \"C\"
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\n" ); document.write( "Similarly: P(80< x < 89) = 14.71% (percent that get \"B\"
\n" ); document.write( "P(90 < x < 100) = 7.92% (percent that get \"A\"
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\n" ); document.write( "I'll leave F and D to you.
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\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.\r
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