The shutter mechanisms of 20 nominally identical cameras are selected and submitted to life test. Failures occur at the following number of operations: 804 1032 1246 1327 1468 1573 1671 1759 After 1800 shutter operations the test was terminated with 12 mechanisms surviving. (a) Plot these data and insert all best estimates (b) From the mean time to failure, estimate: (i) The failure rate per operation (ii) The reliability after 1000 operations (iii) If four such cameras were taken on holiday, what is the probability that all four mechanisms would survive 1000 operations? (Assume that the life test correctly simulated holiday conditions)