Confidence Intervals for Variances and Standard Deviation

The number of carbohydrates in grams per 8 oz serving of yogurt for each of a random selection of brands is listed below. Estimate the true population variance and standard deviation for the number of carbohydrates per 8 ounce serving of yogurt with 95% confidence. 

17 42 41 20 39 41 35 15 43

25 38 33 42 23 17 25 34