2-16-09

# 2-16-09 - 2. The distributions of some estimators become...

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Economic Statistics – Class Notes – 2/16/09 Study Guide Wednesday Will have a list of all the proofs you need to memorize EXAM 2/27/09 The exam will be almost entirely proofs DON’T memorize the steps, MEMORIZE the procedure! If there is a square, run the square through Understand the process D. Important Continuous Distributions and their Properties I have a formula and I’m trying to answer a statistical formula based on this formula o Normal o T o Chi-Square or, o F-Distribution? 1. The Normal Distribution – A symmetric distribution defined by its mean, µ , and standard deviation, , We will be given a Normal/T/Chi-Square/F-Distribution table for use with these problems

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Q: Why is the normal distribution important? A: 1. The normal distribution provides a good description of the distributions of many natural (science) and social (science) statistical population data. a. Examples: i. IQ score ii. Height iii. Weight b. The histograms for such data will appear normal in the long run

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Unformatted text preview: 2. The distributions of some estimators become normal in shape as the sample size gets larger and larger CENTRAL LIMIT THEOREM 3. The STANDARD Normal Distribution – formed (found) by subtracting the mean from a normally distributed random variable and dividing by its standard deviation. a. Example: b. The “i th” element from a random sample given a normally distributed parent population, then: Under what conditions is (Xbar) distributed normally: 1. If the parent population is distributed normally 2. CENTRAL LIMIT THEOREM – If the sample size WHAT IS THIS? 3. The Chi-Square Distribution ( )– A distribution formed by squaring individual independent standard normal random variables and forming their sum a. This is spawned from the normal distribution (sort of) Q: How can we tell (see directly above)? ANSWER: PROVE IT Rewrite until we see the chi-square form...
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## This note was uploaded on 06/03/2009 for the course ECON 203 taught by Professor Casler during the Spring '09 term at Allegheny.

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2-16-09 - 2. The distributions of some estimators become...

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