A machine filling 18 grams containers of hair dye is set to have an average fill of 18.2 grams
with variance 0.49 grams2
. Assume that the filling of the containers is normally distributed
1.1 What percentage of the containers will have a fill of at least 18 grams per container?

1.2 What is the minimum mass of the heaviest 25% of containers?
1.3 A random sample of 25 containers is selected and the mean mass calculated. What is the
probability that this mean will differ from 18.2 by more than 0.2?