An article gives arguments for why fracture toughness in concrete specimens should have a Weibull distribution and presents several histograms of data that appear well fit by superimposed Weibull curves. Consider the following sample of size n = 18 observations on toughness for high-strength concrete (consistent with one of the histograms); values of pi = (i − 0.5) 18 are also given. Observation 0.47 0.60 0.65 0.6 0.72 0.74
Pi 0.0278 0.0833 0.1389 0.1944 0.25 0.3056
Observation 0.76 0.79 0.80 0.8 0.82 0.84
Pi 0.3611 0.4167 0.4722 0.5278 0.5833 0.6389
Observation 0.86 0.89 0.91 0.95 .01 1.05
Pi 0.6944 0.75 0.8056 0.8611 0.9167 0.9722
Construct a Weibull probability plot.