>(%i1) load (descriptive)$
(%i2) /* muestra univariate */   mean ([a, b, c]);
                            c + b + a
(%o2)                       ---------
                                3
(%i3) matrix ([a, b], [c, d], [e, f]);
                            [ a  b ]
                            [      ]
(%o3)                       [ c  d ]
                            [      ]
                            [ e  f ]
(%i4) /* muestra multivariante */ mean (%);
                      e + c + a  f + d + b
(%o4)        