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Inference comparing two groups or populations

AP Stats: DAT (BI), DAT‑3 (EU), UNC (BI), UNC‑4 (EU), VAR (BI), VAR‑6 (EU)
AP Stats: UNC (BI), UNC‑4 (EU), UNC‑4.I (LO), UNC‑4.I.1 (EK), UNC‑4.J (LO), UNC‑4.J.1 (EK), UNC‑4.K (LO), UNC‑4.K.1 (EK)
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Confidence intervals for the difference between two proportionsExamples identifying conditions for inference on two proportionsCalculating a confidence interval for the difference of proportions
Practice
Conditions for inference on two proportionsGet 3 of 4 questions to level up!
AP Stats: DAT (BI), DAT‑3 (EU), DAT‑3.C (LO), DAT‑3.C.1 (EK), DAT‑3.D (LO), DAT‑3.D.1 (EK), DAT‑3.D.2 (EK), UNC (BI), UNC‑4 (EU), UNC‑4.N (LO), UNC‑4.N.1 (EK), VAR (BI), VAR‑6 (EU), VAR‑6.H (LO), VAR‑6.H.1 (EK), VAR‑6.H.2 (EK), VAR‑6.H.3 (EK), VAR‑6.I (LO), VAR‑6.I.1 (EK), VAR‑6.J (LO), VAR‑6.J.1 (EK), VAR‑6.K (LO), VAR‑6.K.1 (EK)
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Hypothesis test for difference in proportionsConstructing hypotheses for two proportionsHypothesis test for difference in proportions exampleComparing P value to significance level for test involving difference of proportionsConfidence interval for hypothesis test for difference in proportions
AP Stats: UNC (BI), UNC‑4 (EU), UNC‑4.V (LO), UNC‑4.V.1 (EK), UNC‑4.V.2 (EK), UNC‑4.W (LO), UNC‑4.W.1 (EK), UNC‑4.X (LO), UNC‑4.X.1 (EK), UNC‑4.X.2 (EK), UNC‑4.Y (LO), UNC‑4.Y.1 (EK), UNC‑4.Y.2 (EK)
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Conditions for inference for difference of meansConstructing t interval for difference of meansCalculating confidence interval for difference of means
Practice
Conditions for inference on two meansGet 3 of 4 questions to level up!
AP Stats: DAT (BI), DAT‑3 (EU), DAT‑3.H (LO), DAT‑3.H.1 (EK), DAT‑3.H.2 (EK), UNC (BI), UNC‑4 (EU), UNC‑4.AA (LO), UNC‑4.AA.1 (LO)
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Hypotheses for a two-sample t testExample of hypotheses for paired and two-sample t testsTwo-sample t test for difference of meansConclusion for a two-sample t test using a P-valueConclusion for a two-sample t test using a confidence interval
Practice
Test statistic in a two-sample t testGet 3 of 4 questions to level up!
P-value in a two-sample t testGet 3 of 4 questions to level up!

About this unit

If a poll from one location shows 55% of voters support a measure, but a poll from another location shows 45% support, does that mean there is a difference between the two populations? We can make a confidence interval to estimate the difference, or do a significance test to see if the difference is significant. We'll use similar methods to compare the means of two groups.
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