Uncertainity Calculation
P has a relative uncertainty of &plusmn;0.15/5 = &plusmn;0.03

A has a relative uncertainty of &plusmn;0.009/0.3 = &plusmn;0.03

When you add/subtract numbers you add their absolute uncertainties.

When you multiply/divide numbers you add their relative uncertainties.

Therefore, the relative uncertainty in P/A is &plusmn;0.03 + &plusmn;0.03 = &plusmn;0.06. The nominal value of P/A is 5/.3 = 16.67, so its absolute uncertainty is 16.67 &times; &plusmn;0.06 = &plusmn;1.0.

You can verify this: The maximum value of P/A occurs when P is maximum and A is minimum: 5.15/0.291 = 17.70. Similarly, the minimum value of P/A occurs when P is minimum and A is maximum: 4.85/0.309 = 15.70.

When you raise a value to a power, you multiply its relative uncertainty by the power. Therefore T has a relative uncertainty of &plusmn;0.06 &times; 1/4 = &plusmn;0.015. The nominal value of T is 16.671/4 = 2.02, so its absolute uncertainty is 2.02 &times; &plusmn;0.015 = &plusmn;0.03.

Again, verify this: The minimum value is 15.701/4 = 1.99 and 17.701/4 = 2.05.