# Find 95% confidence interval for variance and standard devia

You randomly select and measure the contents of 10 bottles of cough syrup. The results are listed

4.212 4.298 4.259 4.243 4.181

4.209 4.269 4.244 4.223 4.237

Assume sample is taken from normally distributed population.

Construct 95% confidence intervals for:

(a) Confidence interval for population variance ____,_____

Round six decimals as needed

(b) Confidence interval for population standard deviation ____,____

https://brainmass.com/statistics/confidence-interval/confidence-interval-variance-standard-devia-480943

#### Solution Preview

First, from the dataset, we could get the variance

S^2=0.001117.

Find the critical values χ2R and χ2L for a 95% confidence interval when the sample size is 10.

Because the sample size is 10, there are 9 ...

#### Solution Summary

The solution provides detailed explanation how to find out the 95% confidence interval for variance and standard deviation.

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