A machine is employed to fill containers with the liquid product. Fill volume can be assumed to be normally distributed. A random sample of 10 containers is chosen and the net contents (oz) are as follows: 12.03, 12.01, 12.04, 12.02, 12.05, 11.98, 11.96, 12.02, 12.05 and 11.99.
a) Assume that the manufacturer wants to be sure that the mean net content exceeds 12 oz. What conclusions can be drawn from data (use alpha=0.01).
b) Develop a 95% two-sided confidence interval on the mean fill volume.
c) Does the assumption of normality seem proper for the fill volume data?