Question1: .A normal population has a mean of 22 and a standard deviation of 3. (Round z value to 2 decimal places.)
[A] The value associated with 28 is ...
[B] The proportion of the population is between 22 and 28 is… (Give your answer to 4 decimal places.)
[C] The proportion of the population less than 18 is … (Give your answer to 4 decimal places.)
Question2: The mean of a normal probability distribution is 480; the standard deviation is 18.
[A] About 95 percent of the observations lie between what two values?
[B] Practically all of the observations lie between what two values?
[C] About 68% of the observations lie between what two values?