1. A particular brand of sugar is sold in 5-lb packages. The weight of sugar in these packages can be assumed to be normally distributed with mean μ = 5 lb and standard deviation σ = 2 lb. What is the probability that the mean weight of sugar in 15 randomly selected packages will be within 0.2 lb of 5 lb?
2. A random sample of size 150 is taken from an in?nite population having the mean μ = 15 and standard deviation σ = 2.5. What is the probability that X will be between 10.5 and 18.5?
3. The distribution of heights of all students in a large university has a normal distribution with a mean of 66 inches and a standard deviation of 2 inches. What is the probability that the mean height of 26 randomly selected students from this university will be more than 70 inches?