ABSTRACT

The coin-tossing data would produce a histogram that looks somewhat like the normal curve. The equation for the continuous normal curve was determined by Abraham DeMoivre, a French mathematician who lived in England about three hundred years ago. When raw scores are converted to standard scores, it is easier to interpret and compare them to each other than when they are in raw score form. The fact that the normal curve is continuous and asymptotic indicates that the curve has some height value for any possible z-score. Much of the usefulness of the standard normal curve in statistics comes from its characteristics. It is unimodal, symmetrical, continuous, mesokurtic, and asymptotic. The mean of the normal distribution is the middle of the distribution, so 50% of the observations are below a z-score of 0.00. Recall that the median and the mean are all equal to each other in a normal distribution.