30. Solving a chemistry problem

12. Quality control of the piracetam preparation (substance) for the content of the sum of foreign impurities W (mass fraction) in it gave the following results in five parallel determinations. %: 0.45; 0.48; 0.50; 0.52; 0.55. The true value of the content of foreign impurities is mu=0.50%. Characterize the reproducibility of the results obtained by calculating the confidence interval of the mean, with a confidence probability of P=0.95 and the presence or absence of a systematic error. Answer: W±ΔW=(0.50±0.05)%. The true value of 0.50% lies within the confidence interval of the mean. There is no systematic error. The method gives correct results.