Suppose we have a population of scores with a mean (ì) of 200 and a standard deviation (ó) of 10. Assume that the distribution is normal. Provide answers to the following questions:

Question

What score would cut off the top 5 percent of scores?
What score would cut off the bottom 5 percent of scores?
What score would cut off the top 2.5 percent of scores?
What score would cut off the bottom 2.5 percent of scores?

Answer 1

Z = (score-mean)/SD

Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the Z scores related to the above proportions. Insert the values into the equation and calculate.