4.2 A sample of 200 resistors is subjected to testing (presumably in the usefullife period). Five failures are found at the end of 500 hours. Six more at the end of 800 hours, 2 more at the end of 1200 hours, 6 more at the end of 1800 hours and no further failures are found when the test is terminated at the end of 2400 hours. a) Estimate the MTBF if no replacements are made. (4 marks) b) Estimate the failure rate of the component ( 1 mark) c) What is the probability that any one of these components will last more than 2500 hours? (1 mark) d) What is the probability that any one of these components will fail before 2000 hrs? ( 1 mark) e) What is the probability of failure within the next 1000 hours, if it has already been in use for 1000 hours? Use a drawing to illustrate your