document.write( "Question 323449: find the value of z such that 40% of the distribution lies between it and the mean. \n" ); document.write( "
Algebra.Com's Answer #231472 by Edwin McCravy(20056)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "The mean of the standard normal curve is at z=0.\r\n" );
document.write( "You want the value of z such that the area under the curve\r\n" );
document.write( "between it and z=0 is .40.  That is, the shaded region below\r\n" );
document.write( "is to be .40\r\n" );
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document.write( "To find that value look in the body, not the z values,\r\n" );
document.write( "but the 4-place decimal values of your table until you find the \r\n" );
document.write( "closest value to .4000.  You find the values .3997 which is the nearest\r\n" );
document.write( "value under .4000, and .4015 which is the nearest above .4000. The closer \r\n" );
document.write( "of these to .4000 is .3997, and the leftmost column on that row is 1.2 and \r\n" );
document.write( "the heading of the column it is in is 0.08, so the value in 1.28.  However,\r\n" );
document.write( "the shaded area is on the left which is the negative side, so the answer is\r\n" );
document.write( "-1.28.\r\n" );
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document.write( "You can also find it on your TI-84 calculator, but on the calculator\r\n" );
document.write( "you have to find the z-value that has the other 10% (50%-40%) to the\r\n" );
document.write( "left of it:\r\n" );
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document.write( "Press ON\r\n" );
document.write( "Prss CLEAR\r\n" );
document.write( "Press 2ND\r\n" );
document.write( "Press VARS\r\n" );
document.write( "Press 3\r\n" );
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document.write( "you should see invNorm(\r\n" );
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document.write( "after that type .1) \r\n" );
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document.write( "you should see  invNorm(.1)\r\n" );
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document.write( "Press ENTER\r\n" );
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document.write( "Read -1.281551567\r\n" );
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document.write( "Round that to -1.28.\r\n" );
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document.write( "Edwin
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