An experiment was conducted to investigate the filling capability of packaging equipment at a winery in Newberg, Oregon. Twenty bottles of Pinot Gris were randomly selected and the fill volume (in ml) measured. Assume that fill volume has a normal distribution. The data are as follows: 753, 751, 752, 753, 753, 753, 752, 753, 754, 754, 752, 751, 752, 750, 753, 755, 753, 756, 751, and 750.
(a) Do the data support the claim that the standard deviation of fill volume is less than 1 ml? Use  = 0.05.
(b) Find a 95% two-sided confidence interval on the standard deviation of fill volume.
(c) Does it seem reasonable to assume that fill volume has a normal distribution?