in reply to Annoying error although module is installed

You're not importing the method before you use it. 

use Statistics::Basic::StdDev 'stddev';

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Untested... could also be: 
use Statistics::Basic 'stddev';

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Hope this helps!

edit: tangent's answer is more complete.


The way forward always starts with a minimal test.

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Re^2: Annoying error although module is installed
by Anonymous Monk on Feb 29, 2016 at 00:21 UTC
    Thank you very much!
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