2.3 is already rounded to the nearest tenth.
16.0
12 cm
The answer will depend on the units used for 10.67 It should be obvious that the answer for 10.67 millimetres will be different from the answer for 10.67 inches!
4.45cm to the nearest cm = 4cm
Its radius is 4.8 cm, rounded to the nearest tenth.
2.7
100.0
2.7cm
Is the same as rounding to the nearest millimetre.
37.7 cm
147.3
The answer depends on the [unspecified] units used for 7.5: if 7.5 micrometres, then to the nearest tenth of a centimetre, it is 0.0 cm.
That rounds to zero.
2.3 cm
8.0
3.0