8. The sugar content in a one-cup serving of a certain breakfast cereal was measured for a sample of 140 servings. The average was 11.9 g and the standard deviation was 1.1 g. a. Find a 95% confidence interval for the mean sugar content. b. Find a 99% confidence interval for the mean sugar content c. What is the confidence level of the interval (11.81, 11.99)?