Biology % uncertaintyWatch
Mean width / mm (± uncertainty / mm) 1.61 (± 0.19)
Mean length / mm (± uncertainty / mm) 6.12 (± 0.41)
Calculate the mean surface area of one side of one gill lamella. Assume that a gill lamella is rectangular and give your answer to an appropriate number of significant figures.
Include the percentage error (uncertainty) of surface area in your answer. Show your working. [3 marks]
ive got the area (9.85mm^2) but i dont understand how to get the % uncertainty (the answer is 18.5-19)