The following lists a set of output voltage values from a group of DUTs together with their measured values: {(2.3, 2.1), (2.1, 1.6), (2.2, 2.1), (1.9, 1.6), (1.8, 1.7), (1.7, 2.1), (1.5, 2.0)}. If the upper specifi cation limit is 2.0 V and the measurement uncertainty is ±0.5 V, how many good devices are rejected due to the measurement error?