document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1116645>Question 1116645</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Find the z-scores for which 90% of the distribution's area lies between -z and z.<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 #731764 by </B><A HREF=/tutors/aboutme.mpl?userid=Theo><B>Theo(13342)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Theo><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=Theo><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=731764\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> the z-score will be plus or minus 1.644853626 from my TI-84 Plus calculator.\r<BR>\n" );
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document.write( "using the following online normal distribution calculator, the z-score will be plus or minus 1.645.\r<BR>\n" );
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document.write( "this is essentially the same z-score except rounded to 3 decimal digits.\r<BR>\n" );
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document.write( "<a  rel=nofollow HREF= \"http://davidmlane.com/hyperstat/z_table.html\" target = \"_blank\">http://davidmlane.com/hyperstat/z_table.html</a>\r<BR>\n" );
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document.write( "here's a picture of what i did using that calculator.\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" src = \"http://theo.x10hosting.com/2018/050901.jpg\" alt=\"$$$\" >\r<BR>\n" );
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document.write( "here's another calculator that i used.\r<BR>\n" );
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document.write( "<a  rel=nofollow HREF= \"http://stattrek.com/online-calculator/normal.aspx\" target = \"_blank\">http://stattrek.com/online-calculator/normal.aspx</a>\r<BR>\n" );
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document.write( "here's a picture of what i did using that calculator.\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" src = \"http://theo.x10hosting.com/2018/050902.jpg\" alt=\"$$$\" >\r<BR>\n" );
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document.write( "this calculator is used more like you would do when looking at a z-score table.\r<BR>\n" );
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document.write( "90% confidence limit means 10% is outside the limits.<BR>\n" );
document.write( "divide this in half and you have 5% outside the limits to the left and 5% outside the limits to the right.\r<BR>\n" );
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document.write( "enter .05 area in the calculator and it will tell you that the z-score is -1.645.\r<BR>\n" );
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document.write( "that tells you that the area to the left of the z-score of -1.645 is equal to .05.\r<BR>\n" );
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document.write( "using the z-score table, you do essentially the same thing, only you can't tell it .05.\r<BR>\n" );
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document.write( "you have to look for an area of .05.\r<BR>\n" );
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document.write( "the table i used is at <a  rel=nofollow HREF= \"http://users.stat.ufl.edu/~athienit/Tables/Ztable.pdf\" target = \"_blank\">http://users.stat.ufl.edu/~athienit/Tables/Ztable.pdf</a>\r<BR>\n" );
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document.write( "look up an area of .05 in the z-score table and you will see that .05 is not in the table.\r<BR>\n" );
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document.write( "you will see an area of .0505 and an area of .0495.\r<BR>\n" );
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document.write( "the z-score for .0505 is -1.64.<BR>\n" );
document.write( "the z-score for .0495 is -1.65.\r<BR>\n" );
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document.write( "the z-score you are looking for is halfway between at -1.645.\r<BR>\n" );
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document.write( "here's a picgture of what i looked for.\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" src = \"http://theo.x10hosting.com/2018/050903.jpg\" alt=\"$$$\" >\r<BR>\n" );
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document.write( "here's the specific line where i found the values i was looking for.\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" src = \"http://theo.x10hosting.com/2018/050904.jpg\" alt=\"$$$\" >\r<BR>\n" );
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document.write( "the first decimal place of the z-score is in the left hand column of the row that .0505 and .0495 are on.\r<BR>\n" );
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document.write( "the second decimal place of the z-score is in the first row of the column that .0505 and .0495 are on.\r<BR>\n" );
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document.write( "you will see .04 in the first row of the column that .0505 is in.<BR>\n" );
document.write( "you will see .05 in the first row of the column that .0495 is in.\r<BR>\n" );
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document.write( "-1.6 + .04 equals -1.64<BR>\n" );
document.write( "-1.6 + .05 equals -1.65\r<BR>\n" );
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