Twenty exponential units from the same production are reliabil- ity tested with immediate replacement of the failed units. Failures occur at the following times: Ti = 350 hr, T2 = 700 hr, T3 = 1,050 hr and T4 = 1,100 hr. At a 95% confidence level do the following: (1) Find the clock hours in this failure terminated test. (2) Find the unit hours of test time required to prove that an MTBF goal of 3,000 hr has been met in a failure terminated test, assuming four failures were allowed in this test. (3) Find the clock hours of test time required in Case 2 to prove the MTBF goal. (4) Given the target MTBF of 3,000 hr, determine the actual confidence level at which this MTBF has been proven based on the results of this test. (5) Find the actual minimum MTBF proven by this test at the 95% confidence level. (6) Determine the total number of units that would have been needed in this test to meet the MTBF goal without any additional failures.