8)

\fI Let X denote the Vibratory stress (psi) on a Wind turbine blade at a particular wind speed in a wind tunnel. Suppose that X has the following Rayleigh pdf. x1:(2ez) f(x)={f)xl92)e x>0 otherwise (a) If 6' = 90, nd the probability that the vibratory stress is between 65 and 301. (b) If 6 = 90, then 90% of the time the vibratory stress is greater than what value