After burn-in, the lifetime of a mechanical valve is known to be lognormal with tmed=2236 hr and s=0.41 (a) determine its design life if specifications call for a reliability of .98 (b)the component is to be used in a pumping device that will require 5 weeks of continous use. What is the probability of a failure occurring because of the valve? (c)compute the MTTF (d) find the standard deviation of the time to failure (e) determine the mode.