15. (8 pts) Propagation of error. Perform the indicated computation and show the result with theappropriate value of uncertainty. Each term is shown as x ± sabs.Y=([(4.255 ±0.004) + (0.0924 ±0.0009)])/(3.632x10^3 ±0.004x10^3)16. (9 pts) Standard Addition Method. Europium(III) ion is determined in an industrial process stream.Samples from the process stream are treated in this manner:(i) 5.00 mL process samples placed in 10.00 mL vol flasks (5 samples were taken)(ii) a known volume of standard is added to each sample (volumes shown in table)(iii) DI water is added as necessary, to bring each sample to 10.00 mL total volume(iv) Concentration of the ADDED STANDARD is calculated. (Given in table)(v) electrochemical current for the reduction of Eu(III) to Eu(II) is recorded.Determine the concentration of Eu(III) in theoriginal process stream samples, (two sig figs.)Added Std.current,sample mL stock conc, mM mA1 0 0 3.572 1 1.00E-01 4.353 2 2.00E-01 5.134 3 5.00E-01 7.475 5 1.00E+00 11.37current, mAEuropium Calibration Curve12.0010.008.006.004.00y = 7.8x + 3.574R² = 12.000.00-0.6 -0.1 0.4 0.9 1.4Concentration, mmol/L