How to create more dimensions for data mining? I want to analyze product sales data with WEKA. My data have attributes: sell quantity and sales price. I want to add more attributes, such as mean and standard deviation.

What formula I should use to create more dimensions?
In general, this is called feature engineering. Expansion of dataset attributes via attribute transformations is called basis function expansion. These are often nonlinear functions of the original attributes. Popular nonlinear functions are polynomials.