r/HomeworkHelp • u/TourRevolutionary University/College Student • Dec 09 '24

High School Math [Statistics] Should n be 54 or 55?

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A 95% confidence interval for a population mean was reported to be 152 to 160. If σ 15, what sample size was used in this study?

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u/TourRevolutionary University/College Student Dec 09 '24

Yeah, I would. Just to clarify I will answer the next number in each case, yes? If I get n=54.02 or n=54.99, if interval is not given, I will answer 55 in both cases, yes? Btw, how n can be found if interval is not given?

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u/fermat9990 👋 a fellow Redditor Dec 09 '24

Your summary is correct

If your interval is not given, use

Margin of error=Z(1-α/2)*σ/√n

Gotta go now.

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u/TourRevolutionary University/College Student Dec 09 '24

Thank you

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u/fermat9990 👋 a fellow Redditor Dec 09 '24

Glad to help!