[R] Sample size required to estimate population variance

[Stephen Ellison]

>  Thanks for the suggestion but I'm not sure that it answers my original
> question.I need to know how many samples I need to collect to collect in
> order to estimate the sample size needed to achieve a specific margin of
> error for confidence intervals for the population variance. I'm not sure
> whether the pwr package does that.

You could consider the case of 50% power, though that'd not be exact for asymmetry.

But if this is a simple univariate data set, it sounds like messing around with chi-squared quantiles and uniroot ought to work. Exactly how are you calculating your confidence limits and which one (upper or lower) needs to be of a specific size?


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