B.4 Distributional Shapes

Figure B.1 illustrates the shapes of some common probability distributions. The value of the random variable is shown on the horizontal axis, and the probability is shown on the vertical axis. These shapes vary with changes in the distributional parameters, such as the variance or degrees of freedom. Notice the symmetry of the normal and the t-distributions and the skew associated with the chi-square and Fdistributions.

Figure B.1. Distributional Shapes