In a nutrition study, 48 pigs were randomly allocated to one of two supplements to their usual feed. Each pig is housed separately in an individual pen. The percentage weight gains (in kilograms) over a month of supplement are recorded. Identify the study design, the outcome and the analysis that can be carried out

(ii) A researcher is interested in determining whether an individual's interest in politics was influenced by their 'education' (primary, secondary or third level) and their 'employment status' (employed or unemployed).

(a)How many factors are used in this experiment? State the name of the factor(s) and the levels of the factor(s).

(b) What is the response variable in this experiment?

(iii)A researcher wishes to know whether there is a difference in the number of kilometres walked daily by retired and non retired individuals. The researcher wishes to obtain 50 measurements from each group. Should 50 readings be taken from one retiree and 50 from non retiree, or should a single reading be taken from each of 50 retirees, and from each of 50 non retirees? Provide a justification for your choice.