A random variable is normally distributed with a mean of 24 and a standard deviation of 4. If an observation is randomly selected from the distribution, a. What value will be exceeded 5% of the time? b. What value will be exceeded 90% of the time? c. Determine two values of which the smaller has 20% of the values below it and the larger has 20% of the values above it. d. What value will 10% of the observations be below?