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Old 05-26-2011
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Stats Systolic blood pressure and confidence interval

In a random sample of 30 patients from a small city, you have measured the systolic blood pressure (SBP). The 95% confidence interval(CI) for the mean SBP is (122,138).
Which of the following statements gives a valid interpretation of this interval?


(a) About 95% of the sample of patiets have a SBP between 122 and 138.
(b) About 95% of the of the patients in that city have a SBP between 122 and 138.
(c) If the sampling procedure were repeated many times, then approximately 95% of the resulting CI would contain the mean SBP for patients in the city.
(d) If the sampling procedure were repeated many times, then approximately 95% of the sample means would be between 122 and 138.
(e) The probability that the sample mean falls between 122 and 138 is equal to 0.95.
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  #2  
Old 05-26-2011
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(e) The probability that the sample mean falls between 122 and 138 is equal to 0.95.
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Quote:
Originally Posted by donofitaly View Post
(e) The probability that the sample mean falls between 122 and 138 is equal to 0.95.
I also think that the right answer is E)
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Old 05-26-2011
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Correct Answer Correct Answer: D

I think it should be D, because CI is defined as a Range of values in which repeated means of sample expected to fall... So in order to get the option E i would likely to see option D to conclude with option E.

Correct Answer: D
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Old 05-26-2011
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i think its e
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Quote:
Originally Posted by bebix View Post
In a random sample of 30 patients from a small city, you have measured the systolic blood pressure (SBP). The 95% confidence interval(CI) for the mean SBP is (122,138).
Which of the following statements gives a valid interpretation of this interval?


(a) About 95% of the sample of patiets have a SBP between 122 and 138.
(b) About 95% of the of the patients in that city have a SBP between 122 and 138.
(c) If the sampling procedure were repeated many times, then approximately 95% of the resulting CI would contain the mean SBP for patients in the city.
(d) If the sampling procedure were repeated many times, then approximately 95% of the sample means would be between 122 and 138.
(e) The probability that the sample mean falls between 122 and 138 is equal to 0.95.
I between c) & d)
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Old 05-26-2011
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I think it's D.

95% CI does NOT equal 95% probability. It is a 95% confidence. It's a nitpicky thing in my opinion
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Old 05-26-2011
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just for diversity... I'll choose C)
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Default erratum ;)

I meant C I guess diversity was illusional
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Correct Answer correct answer

Quote:
Originally Posted by Casandra View Post
I meant C I guess diversity was illusional
very good!

the correct answer is C) If the sampling procedure were repeated many times, then approximately 95% of the resulting CI would contain the mean SBP for patients in the city.

Any one interval from a particular sample may or may not contain the true parameter. In this case, 95% of such intervals that could be constructed from repeated random samples of size n contain the true parameter (in this case μ).

In other words:
-We are 95% confident (or there is a 95% certainty) that the interval contains the "true" parameter (e.g. population mean)
-We are 95% confident that the true parameter is between [lower bound] and [upper bound]

and as Casandra said, 95% CI does not equal 95% probability.
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  #11  
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Very Good question, those were my real 2 answer,, Glad i was close... =) Keep it up....
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Old 06-09-2011
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do u have more questions like this one???
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Old 06-09-2011
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Quote:
Originally Posted by Claus_CU View Post
do u have more questions like this one???
Tomorrow I'll post some more
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