In an experiment the values of refractive index of glass were found to be 2.54, 2.38, 2.74, 2.49, 2.63, 1.45. The relative error and percentage error in refractive index are

μ mean=μ1+μ2+μ3+μ4+μ5+μ66            =2.54+2.38+2.74+2.49+2.63+1.456            =14.236            =2.37    Absolute errors in the measurements are                      ∆μ1=2.54-2.37=0.17                      ∆μ2=2.38-2.37=0.01                      ∆μ3=2.74-2.37=0.37                      ∆μ4=2.49-2.37=0.12                      ∆μ5=2.63-2.37=0.26                      ∆μ6=1.45-2.37=0.92 ∆μmean=Δμ1+Δμ2+∆μ3+∆μ4+Δμ56               =0.17+0.01+0.37+0.12+0.26+0.926               =1.856               =0.31 Relative error=∆μmeanμmean=0.312.37=0.13 % Error=∆μmeanμmean×100=0.13×100=13%