Print this chapterPrint this chapter

More on Normal Distributions


  1. The standard normal distribution is defined as a normal distribution with a mean of 0 and a standard deviation of 1.

  2. Z is equal to the number of standard deviations below or above the mean. Numbers below the mean have negative Z scores.

  3. 25 is 1.5 SDs above the mean: Z = (X - M)/SD = (25 - 16)/6 = 1.5

  4. Z = (X - M)/SD = (6 - 18)/5 = -2.40, Look at the table to see that the area below -2.40 is .0082. (This answer can also be found using the Java applet instead of the table.)