The length of a rod as measured in an experiment was found to be 2.48m, 2.46m, 2.49m, 2.50m and 2.48m. Find the average length, absolute error and percentage error. Express the result with error limit.

Average length= 2.48+2.46+2.49+2.50+2.48/5 = 12.41/5 = 2.48m
Mean absolute error
= 0.00+0.02+0.01+0.02+0.00/5 = 0.05 = 0.013m
Percentage error = 0.01/2.48×100%=0.04×100%
= 0.40%
Correct length = (2.48 ± 0.01)m
Correct length = (2.48m ± 0.40%)