<<< Standard deviation
[IMG]<<<< spearman's rank coefficient.
The standard deviation measures the spread of the data about the mean value. It is useful in comparing sets of data which may have the same mean but a different range.
Spearman's rank correlation coefficient allows you to identify easily the strength of correlation within a data set of two variables, and whether the correlation is positive or negative (whether the slope of the corresponding line is positive or negative).
Alhamdulillaah, I am good. Let me know if you want any help in statistics, I did it in college and school. Yup it is a very common book. Btw, here is a very intensive course that is going on this summer, check it out and see if you could make it... http://www.turntoislam.com/forum/showthread.php?t=68402
Wa 'alaykkumus salaam wa rahmatullaah. How are you akhi? Long time... I just reconfirmed with a hanbali brother, who said that it is obligatory to say it atleast once, and that is what he learnt from 'umdatul fiqh