Chapter 8 271 Nonetheless, the major attraction for evaluating the Weibull parameters involves the ability to reconstruct the best fitting distribution from which they were derived, and in doing so allow for predictions as to the likelihood for survival (or failure) as a function of the number of repeating cycles. (Note: The approach for performing this process in an Excel spreadsheet is also described in Reference 7.) Figure 13 shows the Survival Probability plot resulting from analysis of Caucasian hair at 60% relative humidity under repeated application of stresses in the range 0.010-0.011 g/ μm2. Considering this graph, it is seen that the survival probability is 100% when zero cycles have been applied, with this value dropping as the number of repeated cycles increases. As such, by this approach, it becomes possible to model the probability for fibers failing under different conditions. Figure 13. Survival Probability plot for Caucasian hair under a repeated 0.010-0.011 g/um2 stress at 60% RH