variance problem please help be specific

A ship is carrying 10000 T of wheat from Canada and there is the distinct possibility that part of the cargo is contaminated with T2 mycotoxins. The police informed the port authorities that this particular cargo may contain a fraction of heavily contaminated seeds (up to 4 ppm of the mycotoxin) coming from a specific source (A in table 1). Custom services were able to trace the grains and established two additional sources (B and C). Seeds from sources B and C had been analysed before they were loaded on the ship. No mycotoxin could be detected in the grains from source B, while the grains from source C showed a concentration of 80 ug kg', well below the legal limit. The following sampling protocol was used for this particular analysis under the assumption that the lot to be analysed has a concentration identical to the legal limit of 100 ug kg-: 1. A primary sample of 100 kg is collected as a composite of 50 increments while the ship is unloaded. 2. A secondary sample of 10 kg is then produced on site via quartering and coning 3. The secondary sample is transferred to the laboratory, where it is run five times through a riffle splitter before milling to 400 um diameter 4. A final 2 g sample is collected and analysed. Questions i. Determine the HIL for both the whole grains and the milled material (grains before and after milling have a density of 1.1 g cm-) ii. A preliminary heterogeneity study determined that the standard deviations for the sampling steps are 23.3%, 6.0%, 14.8% for the primary secondary and tertiary sampling respectively. The final step prior to the analysis showed an RSD of 5.7%. Calculate the contributions from the different errors in all the steps. Comment the results. Can you think of a way to improve the TSE? iv. Due to the legal implications, a certified laboratory was asked to repeat the determination and verify the correctness of all the steps. Among other observations, the laboratory established that the MPE for the first step was in fact 7%. Verify numerically whether the two studies are consistent, but consider that the laboratory collected a primary sample made up of 100 increments. Discuss the results. Source Fraction Seed mass (mg) A 10,00% 45 B 50,00% 47 C 40,00% 50 Table 1. Composition of the cargo depending on the three sources