[O] cannot execute org-mode code from the front page tutorial.

[jenia.ivlev]

Hello.

I'm trying to go through the org-mode tutorial on its official page.

However, I have trouble execute the code there"


    #+NAME: tbl-example-data()
    #+BEGIN_SRC R :results value  
    runif(n=5, min=0, max=1)
    #+END_SRC
    
    #+RESULTS: tbl-example-data
    |  0.565871287835762 |
    |  0.457158328965306 |
    | 0.0498181856237352 |
    |  0.988381117349491 |
    |  0.898329895688221 |
    
    
    
    #+NAME: R-mean(x)
    #+BEGIN_SRC R :var x=tbl-example-data
    mean(x)
    #+END_SRC
    
    
    
    
    #+call: R-mean(x=tbl-example-data)


It returns me:



     Reference 'R-mean' not found in this buffer.


Can someone please tell me how can I fix this error?

Thanks in advance for your time and kind help.

Jenia.