her's F-Distribution (from @Statistics.Distribution.FDistribution@)
--
-- > λ> mwc $ listOf 10 (fisher 4 3)
-- > [ 3.437898578540642,0.844120450719367,1.9907851466347173
-- > , 2.0089975147012784,1.3729208790549117,0.9380430357924707
-- > , 2.642389323945247,1.0918121624055352,0.45650856735477335
-- > , 2.5134537326659196 ]
fisher :: PrimMonad m
       => Int
       -> Int
       -> RandT m Double
fisher a b = continuous $ fDistribution a b

-- | Ga
fisher :: PrimMonad m
       => Int
       -> Int
       -> RandT m Double
fisher a b = continuous $ fDistribution a b
fisher a b = continuous $ fDistribution a b