1.1. A supplier of a household disinfectant liquid launched a promotional campaign to increase sales of its 500 ml bottles. Before the campaign, the average weekly sales (in cases sold) were recorded at 12 randomly chosen retail outlets throughout KwaZulu-Natal. Three weeks after the campaign, average weekly sales were again recorded at the same 12 outlets. The average weekly sales (in cases sold) are shown for each of the 12 retail outlets as follows: Sales in cases per outlet before and after the promotional campaign.

	Sales in casesper outlet beforeand after the promotional campaign.
OUTLET	A	B	C	D	E	F	G	H	I	J	K	L
SALES (before)	12	8	14	9	13	15	10	12	10	13	12	10
SALES (after)	12	11	14	9	11	16	11	13	11	13	14	11

Can the suppliers of the household disinfectant conclude that the promotional campaign has been a success? Test this management question statistically. Formulate the null and alternative hypotheses to answer this management question. Conduct a matched-pairs t-test at the 5% significance level. What is your conclusion? (15)

1.2. Chester Butchery supplies Vienna sausages in the entire of KZN province. A meat packer is investigating the marked mass shown on Vienna sausages. A pilot study showed a mean of 11.8kg per pack and a variance of 0.49kg. How many packs should be sampled in order to be 92% confident that the sample mean will differ by at most 0.2kg?