Calculating interest in Haskell
interest :: Float -> Float -> Float
interest capital rate = capital * rate * 0.01

finalvalue :: Float -> Float -> Float
finalvalue capital rate = capital + interest capital rate

finalvalue2 :: Float -> Float -> Float
finalvalue2 capital rate = finalvalue capital rate + interest finalvalue capital rate rate

Couldn't match expected type `Float'
       against inferred type `Float -> Float -> Float'
In the first argument of `interest', namely `finalvalue'
In the second argument of `(+)', namely
    `interest finalvalue capital rate rate'
In the expression:
      finalvalue capital rate + interest finalvalue capital rate rate

interest finalvalue capital rate rate

finalvalue2 :: Float -> Float -> Float
finalvalue2 capital rate =
   finalvalue capital rate + interest (finalvalue capital rate) rate

finalvalue2 :: Float -> Float -> Float
finalvalue2 capital rate =
   finalvalue capital rate + interest finalvalue capital rate rate
                                      ^^^^^^^^^^

finalvalue2              :: Float -> Float -> Float
finalvalue2 capital rate = finalvalue capital rate + interest (finalvalue capital rate) rate