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What is “Statistics”?
Data collection Chapter 1 of text “a way to get information from data” A framework for dealing with variability A way to make decisions under uncertainty Statistical inference: the problem of determining the behaviour of a large population by studying a small sample from that population

Why is statistics important in business?
Financial management (capital budgeting) Marketing management (pricing) Marketing research (consumer behaviour) Operations management (inventory) Accounting (forecasting sales) Human resources management (performance appraisal) Information systems Economics (summarising, predicting) See http://www.youtube.com/watch?v=D4FQsYTbLoI

What is a population? What is a sample?
Population: a collection of the whole of something – e.g. all female students of ANU; all people who live in Tuggeranong; all people who play the flute. Sample: a set of individuals drawn from a population e.g. the female students in STAT1008 are a sample of all female students at ANU.

If we have a population….
We can get parameters – true values for things like the centre and spread of the population We know the answers – what proportion are this tall? We look at the population and get the answer.

If we have a sample…
We can get statistics – these are values that estimate the parameters e.g. sample centre and sample spread used to estimate population centre and population spread We have to use inference to do this estimation – what proportion are this tall? Based on our sample, we would expect….

1

So, statistical inference…
The process of making an estimate, prediction or decision about a population, based on a sample. Note: populations are generally hard to study – large, awkward! So using samples is much more common

Sample or Census
Population: all elements sharing some set of characteristics; comprises the universe for the

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