document.write( "Question 1203818: A distribution of values is normal with a mean of 144 and a standard deviation of 73.2.\r
\n" ); document.write( "\n" ); document.write( "Find P4, which is the score separating the bottom 4% from the top 96%.
\n" ); document.write( "

Algebra.Com's Answer #839657 by Theo(13342)\"\" \"About 
You can put this solution on YOUR website!
mean is 144.
\n" ); document.write( "standard deviation is 73.2
\n" ); document.write( "P4 is the score that separates the bottom 4% from the top 96%.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "use a normal distribution calculator to find the z-score that has 4% of the area under the normal distribution curv to the left of it.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "one such calcuator can be found at https://davidmlane.com/hyperstat/z_table.html\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "this calculator tells you that the the z-score with an area to the left of it of .04 is equal to -1.751.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "use the z-score formula to find the associated raw score.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "the z-score formula is z = (x - m) / s
\n" ); document.write( "x is the z-score
\n" ); document.write( "x is the raw score
\n" ); document.write( "m is the mean
\n" ); document.write( "s is the standard deviation\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "the formula becomes -1.751 = (x - 144) / 73.2
\n" ); document.write( "solve for to get:
\n" ); document.write( "z = -1.751 * 73.2 + 144 = 15.8268.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "P4 is equal to 15.8268.
\n" ); document.write( "that's the score that separates the bottom 4% from the top 96% of the scores when the mean is 144 and the standard deviation is 73.2.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "here's what the calculator results look like.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "
\n" ); document.write( "
\n" );