The Flicks is a small, independent theater that shows foreign and limited-release films. One attraction of the Flicks is that it sells beer and wine as well as premium coffee and pastries at its snack bar. Friday and Saturday nights are the busiest nights at the Flicks, and the owners of the theater are interested in estimating the variance in sales at the snack bar on Friday nights. Suppose a random sample of 14 Friday evenings is selected and the snack bar sales for each evening are recorded. The results of the sample in dollars are as follows:

Use the random sample of sales to develop a 95% confidence interval estimate of the variance of Friday night snack bar sales at the Flicks.