In the Lab you report a measured volume 128.7 of water. Using significant figures as a measure, what range of answers does your reported volume imply

Your measurement implies that the range of answers is 128.6 mL to 128.8 mL.

If you do not state explicitly the range of uncertainty (e. g., ± 0.5 mL), the implied range of uncertainty is ±1 in the last significant digit.

Thus, a reading of 128.7 mL implies that the volume is 128.7 mL ± 0.1 mL.