1 / 4

Analyzing Survey Results and Regression Test to Determine Relationship

This unit discusses hypothesis tests for sample size effects using survey data from Valesky and Brown. It explores confidence intervals and significance tests, determining the relationship between variables using regression analysis.

sylvia
Télécharger la présentation

Analyzing Survey Results and Regression Test to Determine Relationship

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Unit 10: Hypothesis Tests

  2. Effect of sample size • Valesky vs. Brown: Both surveys below say 54% for V., so for CI, EV of sample % is .54. And for sig test: H0: p = 0.5, Ha: p > 0.5. • n = 100: For CI, SE = √[.54(.46)/100] = .05, so 54% ± 10%. For sig test, SE = √[.5(.5)/100] = .05, so P(% ≥ .54) = P(z ≥ (.54-.5)/.05 = .8) = 21% • n = 1600: For CI, SE = √[.54(.46)/1600] = .0125, so 54% ± 2.5%. For sig test, SE = √[.5(.5)/1600] = .0125, so P(% ≥ .54) = P(z ≥ (.54-.5)/.0125 = 3.2) = .07%

  3. Sgn test: Are x,y really related? • Regression line for data in sample approximates the regr line for population: y = α + βx , where α, β are the intercept and slope for the population. • Are population x,y really related, i.e., is β ≠ 0? • Sgn test: H0: β = 0, t = √[n-2]∙r/√[1-r2], df = n-2 • Some statisticians, like our authors, disapprove of this test. (SigT4Slope.ods)

  4. Example: H0: β = 0 t = √[4-2] (.434)/ √[1-(.434)2] ≈ .681 , df = 4-2 = 2 P(t ≥ .681 or ≤ -.681) is not less than 5%, so we fail to reject the null hypothesis: x and y are not related.

More Related