<p>i know this is a bad question i'm about to ask but, seeing as how it kind of surprised me on my math level 2 test (i took it in october), could anyone explain to me what standard deviation is? i'm taking the test again in june and i'm hoping to get that problem right this time. hah. thanks everyone.</p>
<p>Standard deviation is the mean of the difference of each element of a set from the mean.</p>
<p>If a question asks you which set has the greatest or least standard deviation, choose the one that is most or least spread apart, respectively.</p>
<p>If you have a TI-83+, you can enter a list of numbers into the stat list, move one right to CALC, and hit one var stats to find the standard deviation and some other stuff.</p>