Confidence Interval Flowchart

Confidence Interval Flowchart - Small x s 1 2 n 1 + s 2 2 n...

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Confidence Interval Flowchart Parameter Variance known? Variances same? Size? Point estimator Standard error Distribution type D.O.F. Confidence interval Mean, μ Known Irrelevant x σ x n z-distrib. x ± z α /2 x Mean, Unknown — Small x s x n t-distribution n 1 x ± t /2 s x Mean, Unknown — Large x s x n Approx. z x ± z /2 s x Proportion, p Known Irrelevant Crazy Crazy Crazy Crazy Crazy Proportion, p Unknown — Small ˆ p ˆ p (1 ˆ p ) n ??? ??? ??? Proportion, p Unknown — Large ˆ p ˆ p (1 ˆ p ) n approx. z ˆ p ± z /2 s ˆ p Diff. in means, Δ Known Irrelevant Δ x 1 2 n 1 + 2 2 n 2 z-distrib. Δ x ± z /2 Δ x Diff. in means, Δ Unknown Yes Small Δ x ( n 1 1) s 1 2 + ( n 2 1) s 2 2 n 1 + n 2 2 1 n 1 + 1 n 2 t-distrib. n 1 + n 2 2 Δ x ± t /2 s Δ x Diff. in means, Δ Unknown Yes Large Δ x ( n 1 1) s 1 2 + ( n 2 1) s 2 2 n 1 + n 2 2 1 n 1 + 1 n 2 approx. z Δ x ± z /2 s Δ x Diff. in means, Δ Unknown No
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Unformatted text preview: Small x s 1 2 n 1 + s 2 2 n 2 t-distrib. n 1 + n 2 2 (approx.) x t /2 s x Diff. in means, Unknown No Large x s 1 2 n 1 + s 2 2 n 2 approx. z x z /2 s x Diff. in proportions, p Known Irrelevant Crazy Crazy Crazy Crazy Crazy Diff. in proportions, p Unknown Yes Irrelevant Crazy Crazy Crazy Crazy Crazy Diff. in proportions, p Unknown No Small p p 1 ( p 1 1) n 1 + p 2 ( p 2 1) n 2 ??? ??? ??? Diff. in proportions, p Unknown No Large p p 1 ( p 1 1) n 1 + p 2 ( p 2 1) n 2 approx. z p z /2 s p...
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This note was uploaded on 01/11/2012 for the course ECON 400 taught by Professor Turchi during the Fall '08 term at UNC.

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