(a) The linear calibration curve in Figure 4-13 is y 5 0.016 30 (±0.000 22) x 1 0.0047 (±0.0026) with s_y = 0.0059. Find the quantity of unknown protein that gives a measured absorbance of 0.264 when a blank has an absorbance of 0.095.

(b) Figure 4-13 has n = 14 calibration points in the linear portion. You measure k = 4 replicate samples of unknown and find a mean corrected absorbance of 0.169. Find the standard uncertainty
and 95% confi dence interval for protein in the unknown.

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0.40 Unknown beyond linear region 0.35 0.30 Unknown in linear region 0.25 Quadratic 0.20 calibration curve 0.15 0.10 Linear 0.05 calibration curve 0.000 -0.05는 0. 10 15 20 25 Amount of protein (ug) Corrected absorbance