document.write( "Question 189591This question is from textbook saxon algebra 2
\n" ); document.write( ": A set of test scores is normally distributed with a mean of 82 and a standard deviation of 3. What percent of the scores are between 76 and 88?
\n" ); document.write( "I worked it out to: 82-76=6
\n" ); document.write( "88-82=6
\n" ); document.write( "6/3=2
\n" ); document.write( "What is the next step? \n" ); document.write( "

Algebra.Com's Answer #142271 by jim_thompson5910(35256) $\"\"$ $\"About$

You can put this solution on YOUR website!
You're on the right track. What you've found is that the scores between 76 and 88 fall within 2 standard deviations of the mean. Since these scores are normally distributed (ie they fall on the bell curve), this means that 95% of the scores fall between 76 and 88\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Note: 68% of scores fall within 1 standard deviation within the mean. Also, 95% of scores fall within 2 standard deviations within the mean. Finally, 99.7% of scores fall within 3 standard deviations within the mean (these are all approximations of course). This is called the 68-95-99.7 rule or the empirical rule. Unfortunately, this is something to be memorized (but it's very important in statistics)
\n" ); document.write( " \n" ); document.write( "

\n" );