Exercise 3 The end-point obtained by two analysts using the same titration method were as follows: Analyst A 25.03, 25.03, 25.10, 25.14 AnalystB 25.14,25.18,25.16,25.12 a) Is there any difference in precision between the two analysts? ' b) Did the two analysts obtain different mean results? Exercise 4 - The result below gives the amount (mg/mL) of ephedrine hydrochloride found in pharmaceutical preparations of Ephedrine Elixir B.P. by two different methods: derivative ultraviolet spectroscopy and an official assay method (the nominal amount in each sample was 3 mg/mL). Test whether the results obtained by the two methods differ significantly. Sample Derivative Ofcial 1 2.964 _ 2.913 2 3.030 3.000 3 2.994 3.024