The following data relates to the space shuttle Columbia during its first 4486.59 operating hours. The failure data is based on the number of unscheduled maintenance actions, together with the time that action took place. These were maintenance actions undertaken in space and on any component or part making up the space shuttle. In this practical class you will develop a spreadsheet to answer the following questions: 1. Is there any reliability growth during the operation of the space shuttle, and if so what is its extent? 2. What model best describes this data set? 3. What is the predicted MTBF for 7500 hours of operation? 4. Given a maintenance action took place at time 4486.59 hours, what is the probability of another unscheduled maintenance action being required in the subsequent week. 5. What is the probability that there will be 45 failures by time 4600. Shuttle Age at Time of Unscheduled Maintenance Actions (in Hours of Operation) for components within Columbia . 0.3 0.73 1.26 5.7 11.81 16.16 18.92 36.28 51.83 113.29 119.89 209.28 258.14 448.68 459.95 493.41 515.66 537.61 558.11 571.3 731.16 1044.14 1224.98 1361.29 1697.62 1757.59 1818.74 1835.64 1902.11 1923.71 2180.76 2481.13 2688.82 2811.85 2991.86 3424.47 3451.71 3661.8 4230.68 4486.59

The 99% confidence interval for the MTBF at the end of the test is (to the shown number of decimal places):

None of the shown values

Between 158.0 and 509.8 hours

Between 194.3 and 3065.8 hours

Between 181.1 and 1520.7 hours

Between 216.2 and 757.1 hours