Some knowledge comes in probabilistic terms, some in fuzzy terms. These formalisms are drastically different, so it is difficult to combine the corresponding knowledge. A natural way to combine fuzzy and probabilistic knowledge is to find a formalism which enables us to express both types of knowledge, and then to use a combination rule from this general formalism. In this paper, as such a formalism, we propose to use belief functions. For the case when the universe of discourse is the set of all real numbers, we derive new explicit easy-to-compute analytical formulas for the resulting combination.