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Describe what happens to the confidence intervals

 A nurse practitioner working in a dermatology clinic is studying the efficacy of tretinoin in treating women's post partum abdominal stretch marks.  From a sample of 15 women, the mean reduction of stretch mark score is -0.33 with a sample standard deviation of 2.46.  Describe what happens to the confidence intervals if analyses are conducted on progressively larger samples (e.g. at 30, 50, 100 participants).

The smaller the sample, the more accurate prediction is needed.

 

 

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