Multiply the percentage uncertainty by that power. For example, in the calculation of the volume of a sphere using %age uncertainty in V = 3 × %age uncertainty in radius r.
As uncertainty is multiplied by power factor, increases the precision demand of measurement. If the radius of a small sphere is measured as 2.25 cm by a vernier callipers with least count 0.01 cm, then
the radius r is recorded as r = 2.25 ± 0.01 cm
absolute uncertainty = least count = ± 0.01 cm
%age uncertainty in r = (0.01 cm / 2.25 cm) X (100 / 100) = 0.4 %
total percentage uncertainty in V =3 × 0.4 = 1.2%
Thus volume V = (4/3) π r^{3}
= (4/3) X 3.14 X (2.25 cm) ³
= 47.689 cm³ with 1.2% uncertainty
Thus the result should be recorded as V =47.7 ± 0.6 cm³