Estimating the Reliability of the Data The data from these experiments were analyzed us the sta tistical methods described in Chapters 5 8. For each of the standard arsenic solutions and the deer samples, the average of the three absorbance measurements was calculated. The aver age absorbance for the replicates is a more reliable measure of the concentration of arsenic than a single measurement. Least squares analysis of the standard data (see Section 8D was used o find the best strai ne among the points and to calcula the concentrations of the unknown samples along with their statistical uncertai nties and confidence limit Conclusion