<p>I've got some stats homework over some basic statistics stuff. The link below shows my question. Thanks a ton for the help, I'll even give you a virtual pat on the back if you help.
<a href="http://www.geocities.com/clearcollege/mathhomework.pdf%5B/url%5D">http://www.geocities.com/clearcollege/mathhomework.pdf</a></p>
<p>mean is the average, median is whatever number is in the very middle.. like...say you have 4 5 3 9 2.......4 would be the median, because it's the center number..... mode is the number that's repeated the most.... 2 3 8 4 2 9 4 2 4 4 7....4 would be the mode</p>
<p>I figured all of that, but what would the Standard Deviation be?</p>
<p>Thanks</p>
<p>Standard deviation is the square root of the variance which is the sum of the average distances from the mean.</p>
<p>In formula standard deviation equal sqrt(1/(n-1) * sigma(xi - mean)^2)
That's hard to read, I wish there was latex in these forums.</p>
<p>basically...find the mean.... then subtract every value from the mean and square it....then add up all the squares together and divide them by the number of units minus 1</p>
<p>i.e.</p>
<p>you have values A B C D E F G H I J K and say the mean is 4</p>
<p>now you take (A-4)^2, (B-4)^2, (C-4)^2...do that with all of them</p>
<p>now add up all of those together so (A-4)^2 + (B-4)^2 + (C-4)^2...</p>
<p>NOW we'll call that sum X </p>
<p>SOOO between A-K you have 11 units</p>
<p>soooo you have to take the sum of the squares and divide them by the number of units - 1</p>
<p>SOOO it'll be X/(11-1) = X/10</p>
<p>then you just take the square root of that value....and that's your standard deviation</p>
<p>Click on Chapter 1: Scientific Methods </p>
<p>Good visualization of all of them, especially standard deviation. It sounds more complicated than it is, it's just alot of number punching.</p>