Let X denote the vibratory stress (psi) on a wind turbine blade at a particular wind speed in a wind tunnel. Use the Rayleigh distribution, with pdf f(x; Θ) = (x/Θ²) * e^(-x²/(2Θ²)) for x > 0 and 0 otherwise, as a model for the X distribution.
(a) Verify that f(x; Θ) is a legitimate pdf.
(b) Suppose Θ = 131. What is the probability that X is at most 200? Less than 200? At least 200? (Round your answer to four decimal places.)
at most 200
less than 200
at least 200
(c) What is the probability that X is between 100 and 200 (again assuming Θ = 131)? (Round your answer to four decimal places.)
(d) Give an expression for P(X ≤ x).
P(X ≤ x)