Before determining the amount of sodium carbonate in a sample by titration with standard hydrochloric avid the anaylst decide to check the procedure by analyzing a known sample of 98.75 (w/w)% purity. Five replicate determinations of the known gave the following results: 98.71% 98.59% 98.62% 98.44% 98.58%
At the 95% confidence interval is there any evidance that the analysis is giving inaccurate results?