calculus
posted by taz on .
A machine on an assembly line fills cans with quantities of food that are normally distributed with a standard deviation of 0.057 pounds. The mean quantity filled is estimated using a sample of 100 cans. What is the difference between the upper and lower limits of the 95% confidence interval for the mean?
A.0.0057 lb.
B.0.011 lb.
C.0.022 lb.
D.0.11 lb.
E.0.22 lb.

Since 95% of the samples will be within 2 sigma (standard deviations) of the mean, that range will be 0.114 lb wide.
The answer is D