Part 1. Explain the concept of ‘margin of error’ in deciding the size of a sample.
Part 2 – Explain the following terms with an example
Point estimate
Interval estimate
Confidence interval
Confidence limits
Confidence coefficients or critical values.
Part 3 – In a survey carried out in a large city, 170 households out of a random sample of 250 owned at least one pet. Find the 95 per cent confidence interval for the percentage of households in the city who own at least one pet. Does the result support a pet food manufacturer’s claim that 75 per cent of all households have at least one pet?
In all parts, give examples, show graphs, tables, charts, and demonstrate your knowledge and comprehension. In parts where there are calculations, show your excel work, outputs and discuss meaning of results.