A theoretical justification based on a certain material failure

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A theoretical justification based on a certain material failure mechanism underlies the assumption that ductile strength of a material has a lognormal distribution. Suppose the values of the parameters are μ=5 and σ=0.1.

a. Find the mean strength.

b. Find the median strength.

c. What proportion of material specimens have a ductile strength between 110 and 130?.

d. If the smallest 5% of strength values were unacceptable, what would be the minimum acceptable strength?