An article reports that in a sample of 123 hip surgeries of a certain type, the average time was 136.9 minutes with a standard deviation of 22.6 minutes. surgery Approximately how many surgeries must be sampled so that a 99.5% confidence interval will specify the mean to within 3 minutes? (Round the final answer to three decimal places.) The sugar content in a one-cup serving of a certain breakfast cereal was measured for a sample of 145 servings. The average was 11.9 g and the standard deviation was 1.1 g. What is the confidence level of the interval (11.811, 11.989)? (Round the final answer to three decimal places.) The level of confidence is %.