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anonymous

  • one year ago

A field test for a new exam was given to randomly selected seniors. The exams were graded, and the sample mean and sample standard deviation were calculated. Based on the results, the exam creator claims that on the same exam, nine times out of ten, seniors will have an average score within 6% of 80%. Is the confidence interval at 90%, 95%, or 99%? What is the margin of error? Calculate the confidence interval and explain what it means in terms of the situation.

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  1. anonymous
    • one year ago
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    @Loser66

  2. anonymous
    • one year ago
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    @Hero

  3. Loser66
    • one year ago
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    I don't know.

  4. anonymous
    • one year ago
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    Can you mention someone for me please

  5. Loser66
    • one year ago
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    @jim_thompson5910

  6. jim_thompson5910
    • one year ago
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    the key phrase here is `nine times out of ten` which points us to a 90% confidence interval

  7. jim_thompson5910
    • one year ago
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    90% of the confidence intervals generated will have the population parameter we're interested in

  8. anonymous
    • one year ago
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    ok

  9. anonymous
    • one year ago
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    So what would be the margin error

  10. jim_thompson5910
    • one year ago
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    `seniors will have an average score within 6% of 80%` the target is 80%. Basically this is the stated population parameter the 6% is the error from the target. You can go 6% too high, or 6% too low

  11. jim_thompson5910
    • one year ago
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    |dw:1440113642475:dw|

  12. jim_thompson5910
    • one year ago
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    |dw:1440113668269:dw|

  13. anonymous
    • one year ago
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    So basically I was already given the answers within the question.

  14. jim_thompson5910
    • one year ago
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    pretty much

  15. jim_thompson5910
    • one year ago
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    they just wanted you to interpret it a different way

  16. anonymous
    • one year ago
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    ok thank you, so that is it?

  17. jim_thompson5910
    • one year ago
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    yeah there's one more part, but I'm sure you see what the confidence interval is

  18. anonymous
    • one year ago
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    so what does the confidence interval mean? Sorry if I am bothering you

  19. jim_thompson5910
    • one year ago
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    it means that we're 90% confident that the true mean is between 74% and 86% the true mean is usually at the center of the confidence interval

  20. anonymous
    • one year ago
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    Ok Thank you

  21. jim_thompson5910
    • one year ago
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    no problem

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