** simple sbe example
   :PROPERTIES:
   :DATE:     2011-07-10
   :END:

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| 3.5 |
#+TBLFM: @7$1='(sbe mean (lst @1..@6))

#+name: mean
#+begin_src emacs-lisp :var lst=()
  (let ((num (car lst)) (nums (cdr lst)))
    (/ (float (+ num (apply #'+ nums))) (1+ (length nums))))
#+end_src