Help with uncertainty calculation

[jim421616]

Homework Statement:

An equation for the forced convection heat transfer coefficient over oval shapes is h = 12.5*v^0.6 where v = 5 +/- 0.6 m/s (95% confidence interval). Calculate the percentage uncertainty (95% CI) in the value of the convection heat transfer coefficient, to 1 d.p.

Relevant Equations:

h = 12.5*v^0.6

This is from an online quiz. I thought the answer would be
0.6/5 = 0.12
0.12*0.6 = 0.072
∴ 7.2%

but apparently this is wrong. Can anyone help me out please?

 

[haruspex]

Homework Statement:: An equation for the forced convection heat transfer coefficient over oval shapes is h = 12.5*v^0.6 where v = 5 +/- 0.6 m/s (95% confidence interval). Calculate the percentage uncertainty (95% CI) in the value of the convection heat transfer coefficient, to 1 d.p.
Relevant Equations:: h = 12.5*v^0.6

This is from an online quiz. I thought the answer would be
0.6/5 = 0.12
0.12*0.6 = 0.072
∴ 7.2%

but apparently this is wrong. Can anyone help me out please?

0.12*0.6 is only an approximation valid for small percentage errors. 12% is rather large. Use the precise formula.