1.Use margin of error, confidence level, and standard deviation to find the minimum sample size required to estimate an unknown population mean.

Margin of error: $124, Confidence level; 99%, σ = $560


2.Find the margin of error for 95% confidence interval used to estimate the population propprtion.

In a clinical test with 2333 subjects, 50% showed improvement from the treament.



Thank, I'm having a hard time figure how to get the answers here.

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Originally Posted by allabout grey

1.Use margin of error, confidence level, and standard

deviation to find the minimum sample size required to estimate an unknown population mean.

Margin of error: $124, Confidence level; 99%, σ = $560

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Do you have a stats book? If so, this formula should be in there:



You are given all the necessary info. E is the margin of error. You should know what sigma and z are. Look up z for a 99% CI in the z table.

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2.Find the margin of error for 95% confidence interval used to estimate the population proportion.

In a clinical test with 2333 subjects, 50% showed improvement from the treatment.

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Proportions has a minimum sample formula as well.



You have all you need to find E.

Quote:

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Originally Posted by galactus

Do you have a stats book?. If so, this formula should be in there:



You are given all the necessary info. E is the margin of error. You should know what sigma and z are. Look up z for a 99% CI in the z table.





Proportions has a minimum sample formula as well.



You have all you need to find E.

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Thank you, I figure the 1st one. I still confused about p and do i use 0.25 for q?

No, p+q=1. If p=.5, then what does q have to be?