QUESTION 3 125 Marks : A Silty soil containing 15 percent moisture was mixed in a large muller mixer with 5 wt% of tracer consisting of dextrose and picric acid. After 2 minute mixing, 10 random samples were taken from the mix and analyzed calorimetrically for tracer material. The measured concentrations in the sample were, in weight percent tracer, 4.25, 5.94,5.24, 5.08, 4.03, 4.72, 4.20, 5.76, 3.97, 4.55. 1) Calculate the mixing index and 2) standard deviation 3) State whether the mixing is sufficient or not