Hello,

 

I tried to write function mean - average of numeric list.

 

mean::(Fractional a)=>[a]->a
mean a = (realToFrac (sum a)) / (realToFrac (length a))

 

But error occures:

 

              Could not deduce (Real a) from the context (Fractional b)
              arising from a use of `realToFrac'

To correct this function, i rewrite this function:

mean::(Real a, Fractional a)=>[a]->b
mean a = (realToFrac (sum a)) / (realToFrac (length a))

 

Is there most simple way to write this function?

 

Thanks, Nadav