You work for a yogurt company in the quality control division. You are interested in the standard deviation of one of your production lines as a measure of consistency. You gather a random sample of...

You work for a yogurt company in the quality control division.  You are interested in the standard deviation of one of your production lines as a measure of consistency. You gather a random sample of 28 containers and calculate a standard deviation of 6.6 grams of carbs.  Estimate the population standard deviation at a 95% level of confidence.  Round to 3 decimal places where possible.

a)  Find the lower and upper χ2χ2  critical values at 95% confidence:
Lower:     Upper:

b)  Report your confidence interval for σσ:  (  ,  )