document.write( "Question 970787: In 3-4, for a normal standard distribution, determine what percent of the data values are in each given range.
\n" ); document.write( "3. Between 1 standard deviation below the mean and 1 standard deviation above the mean
\n" ); document.write( "4. Berween 1 standard deviation below the mean and 2 standard deviation above the mean\r
\n" ); document.write( "\n" ); document.write( "This question has been bothering me so much, I need help thank you so much
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Algebra.Com's Answer #593449 by Boreal(15235)\"\" \"About 
You can put this solution on YOUR website!
For a normal distribution, z-score is on the left of the table, and the four figures in the table are probabilities.\r
\n" ); document.write( "\n" ); document.write( "1 SD below =0.1586 probability from the left end to z=-1 (50% probability from left end to z=0)
\n" ); document.write( "1 SD above=0.1586 from right.\r
\n" ); document.write( "\n" ); document.write( "That sum is 0.3172\r
\n" ); document.write( "\n" ); document.write( "Subtract from 1, and what is left is between -1 and 1 is 0.6828
\n" ); document.write( "68% of the probability is between -1 and +1 SD\r
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\n" ); document.write( "\n" ); document.write( "From -1 to +2
\n" ); document.write( "0.1584 to the left is excluded as before.
\n" ); document.write( "Go to the z-table, and under 2.0 you see 0.4772, depending on the z-table (might be 0.9772) The 0.4772 is z above 50%; the 0.9772 is the total probability from the left side to z=+2
\n" ); document.write( "+2 has 0.4772 probability (from 50%). \r
\n" ); document.write( "\n" ); document.write( "Another way to do it is to take the 0.9772 (z=2; 2 SDs) and subtract 0.1586, which is to the LEFT of z=-1 (that is not what you want). In between is what you want, and the probability is the difference of the two numbers, 0.8186.
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