document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=971287>Question 971287</A>: <I><SPAN STYLE=\"word-break: break-all;\"> 9. Suppose heights of U.S. adults are normally distributed with a mean of 66.3 and a standard deviation of 4.4 inches.<BR>\n" );
document.write( "(a) Find the height such that 95% of the population is less than this height. (the 9 percentile)<BR>\n" );
document.write( "(b) What percent of US adults are taller than 64 inches?<BR>\n" );
document.write( "(c)  What is the probability that a sample of 18 adults will have a mean height greater than 64 inches?<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #593822 by </B><A HREF=/tutors/aboutme.mpl?userid=Boreal><B>Boreal(15235)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Boreal><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/cgi-bin/show-face.mpl?user=Boreal><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=593822\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> z=( x-66.3)/4.4<BR>\n" );
document.write( "1.644 is the z value for the 95th percentile.\r<BR>\n" );
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document.write( "Multiply by 4.4 inches<BR>\n" );
document.write( "7.24 inches from the mean.  That is x\r<BR>\n" );
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document.write( "66.3+7.24=73.54 inches.\r<BR>\n" );
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document.write( "95% of the population is <= 73.5inches in height.\r<BR>\n" );
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document.write( "Taller than 64 inches\r<BR>\n" );
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document.write( "z=(64-66.3)/4.4\r<BR>\n" );
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document.write( "= -(2.3)/4.4\r<BR>\n" );
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document.write( "= -.5227 \r<BR>\n" );
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document.write( "I want the percentage of the distribution greater than a z-value of -0.5227\r<BR>\n" );
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document.write( "This is 0.699 or 70% of the adults are greater than 64 inches tall.\r<BR>\n" );
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