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Unformatted text preview: IV. Inference.
A. Confidence Intervals for Population Mean. (Ch. 8) B. Hypothesis Tests for Population Mean (Ch. 9) C. Hypothesis Test for Two Population Means (Ch. 10) D. Inference for Pop. Proportions (Ch. 11) 1. The Sampling Distribution for p 2. Confidence intervals for π 3. Hypothesis tests for π 4. Two Sample tests for proportions. C. Inference for Population Proportions
1. Sampling Distributions for Proportions Population proportion – a parameter: Sample proportion – an estimate π: ResEc 211 Survey Results: Did Did you bring with you a …
Item TV Stereo 2004 0.614 0.468 2006 0.671 0.389 0.209 0.783 2007 2008 2009 0.619 0.618 0.314 0.270 0.181 0.086 0.808 0.900 Desktop 0.475 Laptop 0.479 1 1. Sampling Distributions for Proportions Sampling Distribution for Sample Proportion Three Characteristics of Interest: • Shape: When is the S.D. normal? 1. Sampling Distributions for Proportions • Center: • Variation: Sampling Error = Standard Error – 2. Confidence Interval for Pop. Proportion (π ) Point Estimation: use the sample proportion Confidence Interval: we don’t know π . 2 2. Confidence Intervals for Pop. Proportion (π) Margin of Error: Determining Sample Size. • Rearrange equation for e and solve for n: 1. Sampling Distributions for Proportions Parameters for sampling distributions.
Example: Population Population proportion 2007 ResEc 211 students who brought a TV. For For samples of size 16 and 25, determine the mean and standard errors of the sampling distributions for the sample proportion. What What should we expect to see when comparing these sampling distributions? 3 ...
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This note was uploaded on 12/08/2011 for the course ECON 211 taught by Professor Daniellass during the Spring '11 term at UMass (Amherst).
- Spring '11