Two machines are used for filling glass bottles with a soft-drink beverage. The filling processes have known standard deviations s1= 0.010 liter and s2= 0.015 liter, respectively. A random sample of n1= 25 bottles from machine 1 and n2= 20 bottles from machine 2 result in average net contents of width== 2.04 liters and width= 2.07 liters.
(a) Test the hypothesis that both machines fill to the same net contents, using a = 0.05. What are your conclusions?
(b) Find the P-value for this test.
(c) Construct a 95% confidence interval on the difference in mean fill volume.