  The ability to evaluate the outcomes of quantum annealers is essential for
such devices to be used in complex computational tasks. We introduce a
statistical test of the quality of Ising-based annealers' output based on the
data only, assessing the ground state's probability of being sampled. A higher
probability value implies that at least the lower part of the spectrum is a
part of the sample. Assuming a plausible model of the univariate energy
distribution of the sample, we express the ground-state energy and temperature
as a function of cumulants up to the third order. Using the annealer samples,
we evaluate this multiple times using Bootstrap resampling, resulting in an
estimated histogram of ground-state energies and deduce the desired parameter
on this basis. The approach provides an easily implementable method for the
primary validation of Ising-based annealers' output. We demonstrate its
behavior through experiments made with actual samples originating from quantum
annealer devices.
