The uncertainty (standard deviation) in a single buret reading for a 50-mL buret is about +/- 0.02 mL. Two readings (initial volume and final volume) are required to deliver a specified volume of titrant. For a delivered volume of 6.25 mL, compute the uncertainty in the volume of titrant delivered. Report your result as the relative standard deviation in parts per thousand, to the nearest 0.1 ppt.