document.write( "Question 155351This question is from textbook COLLEGE ALGEBRA
\n" ); document.write( ": Ingrid scored 65 on her calculus midterm. If her final exam score counts twice as much as her midterm exam, then for what range of scores on her final would she get an average between 79 and 90? Hint: For this weighted average multiply the final exam by 2 and the midterm score by 1. \n" ); document.write( "
Algebra.Com's Answer #114404 by Edwin McCravy(20055)\"\" \"About 
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Ingrid scored 65 on her calculus midterm. If her final exam score counts twice as much as her midterm exam, then for what range of scores on her final would she get an average between 79 and 90? Hint: For this weighted average multiply the final exam by 2 and the midterm score by 1.
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document.write( "Let X = her score on the final exam:\r\n" );
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document.write( "Then\r\n" );
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document.write( "\"Average+=+%281%2A65%2B2%2AX%29%2F%281%2B2%29\"\r\n" );
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document.write( "\"Average+=+%2865%2B2X%29%2F3\"\r\n" );
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document.write( "We want:\r\n" );
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document.write( "\"79%3C=%2865%2B2X%29%2F3%3C=90\"\r\n" );
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document.write( "Multiply through by 3 to clear of fractions:\r\n" );
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document.write( "\"3%2A79%3C=65%2B2X%3C=3%2A90\"\r\n" );
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document.write( "\"237%3C=65%2B2X%3C=270\"\r\n" );
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document.write( "Subtract 65 from all three sides:\r\n" );
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document.write( "\"237-65%3C=2X%3C=270-65\"\r\n" );
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document.write( "\"172%3C=2X%3C=205\"\r\n" );
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document.write( "Divide through by 2\r\n" );
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document.write( "\"172%2F2%3C=2X%2F2%3C=205%2F2\"\r\n" );
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document.write( "\"86%3C=X%3C=102.5\"\r\n" );
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document.write( "But we have to cut it off at 100, so\r\n" );
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document.write( "\"86%3C=X%3C=100\"\r\n" );
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document.write( "Her grade must be greater than or equal to 86.\r\n" );
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document.write( "Note: It is impossible for her to end up with an\r\n" );
document.write( "average greater than \"88\"\"1%2F3\". \r\n" );
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document.write( "Edwin
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