ABSTRACT

Example: We want to know if the series of peak discharges discussed above follows a normal distribution. Let Z be the random variable representing the discharges. We can have the following null and alternative hypotheses:

(9.16)

The two parameters of the normal distribution are estimated by the sample average and the sample variance, respectively. This gives us:

Then we proceed to divide the observations into 12 classes – this is an arbitrary choice - and after calculating the observed and theoretical frequencies, we finally

obtain = 14.12.