Hello I also am learning how to use mathematica to do something elementary statistics, so I would like to learn together, if your want, I would like to try to help you in your project.

Some commands that you can use are:

Mean,Median,Variance, StandardDeviation,Covariance,Quantile,Kurtosis,Skewness.

Looking at the documentation there may be the command that you need,there are many commands that can deal with and which are already programmed in mathematica

In my a University we have Mathematica 7, for which we are in the same version, can you tell me what is your project? So as to be able to help you a little more, I have one that I made but is in spanish ,but if you're keen sent it to your email to see how I use some of Mathematica commands

Thank so much Luis, yes I want ,this commands which I need , how I can program it ??? give me some basic commands to understand that

Also we have another commands like : the frequency distribution and graph it by( histogram . polygon , pie graph),p-th percentiles,box plot .