Yahoo Answers: Answers and Comments for Help with AP statistics!!? [Mathematics]
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From Niloy
enUS
Mon, 16 May 2011 10:47:03 +0000
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Yahoo Answers: Answers and Comments for Help with AP statistics!!? [Mathematics]
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https://answers.yahoo.com/question/index?qid=20110516104702AAIBQkq
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From Empire539: You can't, really. The problem relies on c...
https://answers.yahoo.com/question/index?qid=20110516104702AAIBQkq
https://answers.yahoo.com/question/index?qid=20110516104702AAIBQkq
Mon, 16 May 2011 20:25:19 +0000
You can't, really. The problem relies on conceptual knowledge of confidence intervals, and asks you to determine the confidence level. While the TI83/84/Plus/SE calculators can give you a confidence interval given proportions, a confidence level and sample size, it cannot give you individual components.
The margin of error for a zconfidence interval is ME = z*√(p(1 − p)/n), where z* is the critical zscore (which can be converted to a level of confidence), p is the probability, and n is the sample size. In this problem, ME is 3%. You should just be able to plug in the values and solve for z*, which you can then use to determine the confidence level.
ME = z*√(p(1 − p)/n)
.03 = z*√(.832(1 − .832)/n)
z* = .03/√(.832(1 − .832)/n)
z* ≈ 2.54
which corresponds to about a 99% confidence level.