You are in-charge of a Chicago subway project. You were about to start placing concrete according to design specifications. As the in-situ material might significantly vary from what was assumed during the design, you have decided to drill and obtain samples. The shear strength measurements (in ksf) of 13 of undisturbed samples of clay are tabulated below: Sample # Measurement Sample # Measurement
1 0.35 8 0.58
2 0.40 9 0.68
3 0.41 10 0.70
4 0.42 11 0.75
5 0.43 12 0.87
6 0.48 13 0.96
7 0.49
a) Develop a Q-Q plot assuming that data come from log-normal distribution.
b) Estimate the parameters of the distribution.
c) Test the goodness-of-fit of the log-normal distribution using Kolmogorov- Smirnov (K-S) test at 5% significance level.