Abstract
This paper proposes a quantum circuit for computing the mean value from a given set of numbers or function evaluations. Suppose a Quantum Random Access Memory is given as a black-box function, which allows us to store and read the values of a set as quantum states. The proposed quantum algorithm estimate the mean value of the function by using superposition, interference, and entanglement phenomena, in O(logN) complexity or in O(1) query of the black-box.