上記ご回答に対し、データシートのELECTRICAL CHARACTERISTICSのVout=±1.5%(max)とあり、注記(4)でThe stated limit of the set-point voltage tolerance includes the tolerance of both the internal voltage reference and the internal adjustment resistor. The overall output voltage tolerance will be affected by the tolerance of the external RSET resistor.と書かれています。