if falls outside CI REJECT Chapter 11 Hypothesis Test 1 Ho o HA or or o 2 T Stat 3 4 If t obs t reject Ho If t obs t Fail to reject Ho Confidence Interval CI Standard of Error Margin of Error Sample Size Always round up 2 Only if 1 is less than 60 Use n from above 1 Errors We are sure that on average is between and Assumptions for T model independence randomization sample size no more than 10 of population and nearly normal Standardizing T Stat 90 95 98 99 Z 1 645 1 960 2 326 2 576 Type I Reject null hypothesis and its actually true Type II Should have rejected null hypothesis and didn t 99 9 3 29 Chapter 12 For two groups Regular Two sample t test CI P value find T stat and look for it in alpha table then find mean of alphas it is between Pooled SD or Variance of both groups is the same Paired Dependent Before and After d 1 2 Ho d 0 HA d or or 0 CI Compare 0 to CI Chapter 14 Se spread about the regression estimate of SD CI for B1 slope B1 t n 2 SE b1 SE b1 CI for B0 B0 t n 2 SE b0 SE b0 CI for a value Unusual Points Chapter 15 Source Model Regression Residual Error Total DF k n k 1 n 1 1 High Leverage x value is far from mean 2 Influencial Points line without this point would change significantly 3 Large residual big difference in y value but x values are similar SS SSR SSE SST MS MSR SSR k MSE SSE n k 1 MST SST n 1 F F MSR MSE P P value SST total variation SSR amount of variability explained by regression model SSE amount of variability explained by error H0 B1 B2 Bx 0 HA At least one B 0 DF n k 1 Estimate t n k 1 SE R2 how much variability SSR SST R2 adj 1 MSE MST Standard error about regression line se Residuals observed predicted Things to Remember 1 tailed specify 2 tailed Not specified Greater than right tailed Less than Left tailed P value reject P value failed to reject Based on ANOVA p value
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