(a) The black points show the ratio of the observed energy spectrum to the expectation in the case of no oscillation in the neutrino-dominated beam of MINOS. The blue region shows the statistical precision expected from MINOS+. (b) The black line shows the muon neutrino survival probability in the case of no sterile neutrinos; the red line shows how the probability would be modified by the addition of mixing with a sterile neutrino.