The Air Force maintains enormous amounts of data on engine failure times. A particular engine has experienced a failure pattern whose failure rate function is closely approximated by r (t)  0.000355e2.2t, where t is in flying hours.

a. What are the reliability and the cumulative distribution functions of the time until failure?

b. Determine the value of t such that the likelihood that an engine fails before t is the same as the likelihood that an engine fails after t.