CONFIDENCE_INTERVAL-Two_populations-_Final

# CONFIDENCE_INTERVAL-Two_populations-_Final - 2 〉 30): [ ]...

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CONFIDENCE INTERVAL FOR THE DIFFERENCE OT TWO MEANS 1) The two populations normal, variances of the two populations known: [ ] 2 2 2 1 2 1 2 / 2 1 2 1 2 / 2 1 2 1 2 1 2 1 )% 1 ( . . n n where Z X X Z X X P X X X X X X σ α μ + = - = + - - - - - - - 2) The two populations not normal, variances of the two populations known, sample sizes large (n 1 and n 2 30): [ ] 2 2 2 1 2 1 2 / 2 1 2 1 2 / 2 1 2 1 2 1 2 1 )% 1 ( . . n n where Z X X Z X X P X X X X X X + = - = + - - - - - - - 3) The two populations normal or not too skewed, variances of the two populations unknown, sample sizes small (n 1 and n 2 ≤30): [ ] )% 1 ( . . 2 1 2 1 2 / 2 1 2 1 2 / 2 1 - = + - - - - - - X X X X S t X X S t X X P where 2 1 1 1 2 1 n n S S pooled X X + = - 2 1 2 1 2 2 2 2 1 1 1 1 2 ) 1 ( ) 1 ( n n n n S n S n + - + - + - = 4) The two populations normal or not, variances of the two populations unknown, sample sizes large (n 1 and n

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Unformatted text preview: 2 〉 30): [ ] )% 1 ( . . 2 1 2 1 2 / 2 1 2 1 2 / 2 1-= +-≤-≤----X X X X S Z X X S Z X X P where 2 2 2 1 2 1 2 1 n S n S S X X + =-CONFIDENCE INTERVAL FOR THE DIFFERENCE OF TWO PROPORTIONS [ ] )% 1 ( . . 2 1 2 1 2 / 2 1 2 1 2 / 2 1 α σ π-= +-≤-≤----P P P P Z P P Z P P P where ) 1 1 )( ˆ 1 ( ˆ 2 1 2 1 n n P P +-=-where ˆ = 2 1 2 2 1 1 n n p n p n + + = 2 1 2 1 n n X X + +...
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## This note was uploaded on 12/30/2010 for the course BUSS 202 taught by Professor Ritageutchian during the Three '10 term at Notre Dame AU.

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CONFIDENCE_INTERVAL-Two_populations-_Final - 2 〉 30): [ ]...

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