Question
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:
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?
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?
Answers
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 that corresponds to those proportions. Put the values in the above equation and solve for the scores.
Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the Z scores that corresponds to those proportions. Put the values in the above equation and solve for the scores.