see Aarset (1987). Aarset (1987) showed that the scaled TTT
transform is concave (convex) if the hazard function is increasing
(decreasing). To check the shape of the empirical hazard function,
we have plotted the scaled TTT transform in Figure 1. Because
it is a concave function, it indicates that the hazard function
of the distribution will be an increasing function. Therefore,
Rayleigh distribution can be used to analyze this dataset.