document.write( "Question 780945: The number of words in the active vocabulary of children of a particular age is normally distributed with a mean of 3000 and a standard deviation of 500. Using the normal curve approximation rules, how many words would a child of this age have to know to be in the top 2%, the top 16%, and the top 98%? \n" ); document.write( "

Algebra.Com's Answer #475819 by stanbon(75887) $\"\"$ $\"About$

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The number of words in the active vocabulary of children of a particular age is normally distributed with a mean of 3000 and a standard deviation of 500.
\n" ); document.write( "Using the normal curve approximation rules,
\n" ); document.write( "how many words would a child of this age have to know to be
\n" ); document.write( "in the top 2%:::
\n" ); document.write( "invNorm(0.98) = 2.0537
\n" ); document.write( "x = 2.0537*500 + 3000 = 4026.87
\n" ); document.write( "-----------------------
\n" ); document.write( "the top 16%
\n" ); document.write( "invNorm(0.84) = 0.9945
\n" ); document.write( "x = 0.9945*500+3000 = 3497.23
\n" ); document.write( "-----------------------
\n" ); document.write( "the top 98%?
\n" ); document.write( "invNorm(0.02) = -2.0537
\n" ); document.write( "x = -2.0537*500+3000 = 1973.13
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\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.
\n" ); document.write( "=================
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