Guile 3.0.3. The reference manual and the docstring of number->string say: "If N is inexact, a radix of 10 will be used." But that is not what happens, e.g.,
(let ((x 4.0)) (and (inexact? x) (number->string x 3))) evaluates to "11.0" instead of #f or "4.0". Probably "if RADIX is not supplied, a radix of 10 will be used" is meant.