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REGRESSION MODELLING
WEEK 1
Abhinav Mehta
REVISION OF BASIC STATISTICS
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POPULATION AND SAMPLE
Population (True world)
• A collection of the whole of something you are interested in.
• Parameters: true values describing the population, for example
µ, σ2. Usually they are unknown.
Sample (Your subjective world)
• A set of individuals randomly drawn from a population.
• Statistics: calculated from the sample served as estimators of
the parameters, for example X¯ , S2.
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PROPERTIES OF ESTIMATORS
• It is a random variables, e.g., X¯ .
• It has a probability distribution, often called sampling distribution.
• E(X¯ ) = µ, Var(X¯ ) = σ2/n.
• Central Limit Theorem (CLT): X¯ is asymptotically normally
distributed.
• Make statistical inferences: confidence interval and hypothesis
testing.
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REGRESSION