transforming statistics into Z-scores (and soon t-scores), and then calculating the probability of being above or below that score, or between two scores. Many tools are available online to help understand normal distributions, how to come up with standardized values (z-scores), and how to find probabilities associated with various z-scores (aside from using the standard normal table).

Two examples are the following websites: http://ncalculators.com/statistics/z-score-calculator.htm, http://psych-www.colorado.edu/~mcclella/java/normal/normz.html andhttp://www.zscorecalculator.com/index.php. Think of the growth charts when you went to the doctor as a child. What percentile were you in? What percent of your age group were below you or above you? What percent were between you and the average?These are the types of calculations we need to do with Z-(or t-)scores. We willtranslate anyvalue into its distance from the mean, plus or minus, and then we can say what percentile it is. 50% will be below the mean, and 50% above in our normal curves. Compare scores in your textbook to what you get with these tools. Once you have them figured out, you should be able to use these to help with homework.