SOLUTION: Random sample of size 100 has a standard deviation of 5.What can be said about maximum error with 95% confidence?

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Question 885317: Random sample of size 100 has a standard deviation of 5.What can be said about maximum error with 95% confidence?
Answer by Theo(13342) About Me  (Show Source):
You can put this solution on YOUR website!
sample size = 100
standard deviation = 5.
standard error = standard deviation divided by square root of sample size.
standard error = 5/sqrt(100) = 5/10 = .5
two sided alpha for two sided confidence limit of 95% is calculated below:
two sided alpha = (100% - 95%) / 200 = 5% / 200 = .025
critical z factor for two sided alpha of .025 is calculated below:
critical z factor = z factor for (1 - .025) = z factor for .975 = 1.96
margin of error = critical z factor * standard error = 1.96 * .5 = .98
confidence interval = mean plus or minus margin of error = mean plus or minus .98
since you don't have a mean, you can't calculate the confidence interval.
your maximum error with 95% confidence level is equal to plus or minus .98 from the mean.