Final answer:
The 95% confidence interval estimate of a population variance when a sample variance of 324 is obtained from a sample of 81 items can be calculated using the chi-square distribution.
Step-by-step explanation:
The 95% confidence interval estimate of a population variance can be calculated using the chi-square distribution. The formula for calculating it is:
(n-1)s^2 / X^2_1-a/2, n-1
where s^2 is the sample variance, n is the sample size, and X^2_1-a/2, n-1 is the chi-square value for a given level of significance (a) and degrees of freedom (n-1).
In this case, the sample variance is 324 and the sample size is 81. To calculate the confidence interval, you need to find the chi-square value corresponding to a 95% confidence level with 80 degrees of freedom. You can use a chi-square table or a calculator to find this value. Once you have the chi-square value, substitute the values into the formula to calculate the confidence interval estimate of the population variance.