stat400lec29 - for p Answer[0.4997489 0.5005615(b There was...

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Statistics 400 Section 7.5 Confidence Intervals for Proportions Binomial distribution Let Y ~ b(n,p) Objective: construct confidence interval for p W= ) 1 ( p np np Y - - = n p p p n Y / ) 1 ( / - - N(0,1) “sufficiently large”: np 5 and n(1-p) 5 Ping Ma Lecture 29 Fall 2005 - 1 -

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Let Y1 ~ b(n 1 ,p 1 ), Y2 ~ b(n 2 ,p 2 ), Y1 andY2 are independent Objective: construct confidence interval for p 1 -p 2 W= 2 2 2 1 1 1 2 1 2 2 1 1 / ) 1 ( / ) 1 ( ) ( / / n p p n p p p p n Y n Y - + - - - - N(0,1) Ping Ma Lecture 29 Fall 2005 - 2 -
Example : Presidential vote in Florida (2000) Ping Ma Lecture 29 Fall 2005 - 3 -

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(a) The 2000 Presidential election was very close. The result depended on the the final Florida vote tally. In the original vote, the number of votes for Bush is 2,910,136 and the total number of votes for two major candidates (Gore and Bush) is 5,816, 467. Let p be the probability that voters for the two major candidates voted for Bush. Construct 95% confidence intervals
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Unformatted text preview: for p. Answer [0.4997489, 0.5005615] (b) There was a recount after October 10, 2000 in Florida. In the recount, the number of votes for Bush is 2,910,198 and the total number of votes for two major candidates (Gore and Bush) is 5,820,069. Construct 95% confidence intervals for p. Ping Ma Lecture 29 Fall 2005- 4 -Example: Two detergents were test for their ability to remove stains of a certain type. The first one succeeded in 63 out of 91 independent trials and the second one succeeded in 42 out of 79 trails. Let p1 and p2 be the probability of removing stains for two detergent respectively. Construct 95% confidence interval for p1-p2 Ping Ma Lecture 29 Fall 2005- 5 -...
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This note was uploaded on 07/24/2008 for the course STAT 400 taught by Professor Tba during the Fall '05 term at University of Illinois at Urbana–Champaign.

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stat400lec29 - for p Answer[0.4997489 0.5005615(b There was...

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