Study questions

1. Write a summary of the results given for the six livestock species suitable for a scientific audience. Assume in your summary that no particular stratification was applied and that dip-tank areas were not selected at random but chosen to give a widespread representation of a sub-region.

2. Repeat the calculations in CS12Data1 for Scenario 1 for cattle but replace the formula S_T² = [(T₁ - T) ² + ... + (T_n - T)²] / (n-1) by S_T² = [(T₁ -M₁) ² + ...+ (T_n -M_n) ²] / (n-1). Compare the confidence limits with those obtained for Scenario 1 in this case study.

3. The numbers of the different livestock species per homestead are not normally distributed. Apply the logarithmic transformation to the numbers of animals per homestead and repeat the calculations in CS12Data1 and CS12Data2 for cattle. Express the population results in terms of an estimated total together with confidence limits. Comment on the results.

4. Assume that strata are selected in sub-region i that define areas of different livestock density. Assume that m_ij homesteads are now sampled from each stratum and that each stratum contains M_ij homesteads (j=1... r). Write down the algebraic formulae that you will now need to estimate the total number of cattle in sub-region i .