Question

Shear strength measurements derived from unconfined compression tests for two types of soils gave the results shown in the following summary statistics (measurements in tons per square foot).

Summary Statistics

Soil Type I: Sample size = 25, Sample mean = 1.65, Sample std = 0.26

Soil Type II: Sample size = 31, Sample mean = 1.43, Sample std = 0.22.

Do the soils appear to differ with respect to the variability of shear strength? Preliminary data analyses and other information indicate that it is reasonable to assume that the variable under consideration is normally distributed. Use the critical-value approach to perform a test of hypothesis at a 1% level of significance.

(Perform the 5 step hypothesis testing)

Answer 1