# Statistics > Confidence Intervals > 1-Population Variance

This utility computes the confidence intervals for a population variance in one population. The confidnece intervals are calculated using the following formula:

where
n = sample size
s = sample standard deviation
&sigma2 = variance
= inverse cumulative probability of the Chi-square distribution at α/2.
= inverse cumulative probability of the Chi-square distribution at 1 - α/2.
To use the utility, select Statistics > Confidence Intervals > 1-Population Variance.

- You can provide sample data in a column of the Datasheet or provide summary data. To provde sample data in a column, select the Samples in column: radio button, and select the column name in the given drop-down menu.
- If individual sample data is not available, you can provide summary information of the sample data. In this case, select the Summarized sample data radio button. Enter sample size and either sample variance or sample standard deviation in the provided text boxes.
- Enter the confidence level (between 0 and 1) in the Confidence level: text box.
- Click OK to compute the confidence interval. The results will be shown in the log window.

The sample size, variance, and standard deviation are displayed, along with the resulting confidence interval for variance and standard deviation. Here is an example:
Confidence Interval - One population variance: confidence level = 0.95
Input: Summary data

N | Variance | Stdev | 95.00%CI Variance | 95.00%CI Stdev
100 | 10.000 | 3.162 | (7.7090, 13.4949) | (2.7765, 3.6735)