which is 1/3.46 = 0.29 kg.

In the case the null hypothesis is true, the p value from any exact significance test is uniformly

distributed between 0 and 1.

© John Wiley & Sons, Inc.

FIGURE 24-1: The uniform distribution.

The Microsoft

generates a random number drawn from the

standard uniform distribution.

The Normal Distribution

The most popular and widely-used distribution is the normal distribution (also called the Gaussian

distribution and the probability bell curve). It describes variables whose fluctuations are the

combined result of many independent causes. Figure 24-2 shows the shape of the normal distribution

for various values of the mean and standard deviation. Many other distributions (binomial, Poisson,

Student t, chi-square, Fisher F) become nearly normal-shaped for large samples.

The Microsoft

generates a normally

distributed random number, with

and

.

© John Wiley & Sons, Inc.

FIGURE 24-2: The normal distribution at various means and standard deviations.

The Log-Normal Distribution