Let X be the diameter (in mm) of a seed of a certain plant. It can be shown that

ln(X) is normally distributed with mean = 0:68 ln(mm) and = 0:22 ln(mm):

(a) Compute P(X > 2) and P(X<=1).

(b) Find the 50-th percentile of X, i.e. nd a value x0 such that P(X <= x0) = 0:5.