I tried approaching the question through model free estimation, but I'm confused in approaching it through which type of distribution and the two distinct variables. How should I approach the question? Thank you!

Use the following for questions 10 and 11. Suppose we want to estimate the concentration of a specific dose of ampicillin in the urine a short period of time after ingestion. We recruit 45 volunteers who receive ampicillin and they have a mean concentration of 6.9 g/ml with a standard deviation of 2.9 g/mL. What is the 95% confidence interval for the population variance of the concentrations? O (8.05, 8.80) O (5.76, 13.42) O (6.03, 7.77) O (1.99, 4.63)What assumption do we need to make for our confidence interval to be valid? O The population has a normal distribution. O No assumptions are needed since n > 30. The population variance is known. O no- 2 8 and n(1 - 63) > 8