A jar of peanuts is supposed to have 16 ounces of peanuts. The filling machine inevitably experiences fluctuations in filling, so a quality-control manager randomly samples 12 jars of peanuts from the storage facility and measures their contents. She obtains the accompanying data. Complete parts (a) through (d) below.

The data's

23.93 23.75 24.21 23.47 23.87 23.86

23.43 24.18 23.82 23.61 24.28 24.59

1. Verify that the data are normally distributed by constructed a normal probability plot
2. Determine the sample standard deviation.
3. Construct a 99% confidence interval for the population standard deviation of the number of ounces of peanuts. Select the correct choice below and fill in the answer boxes to complete your choice. (Use ascending order. Round to three decimal places as needed.