Air Raid Inc. designed 20 air-conditioning systems designed for use by astronauts in the International Space Station. All of them were operated for 1,000 hours at NASA's test facility. Out of all the systems 2 of them failed during the test. One of them after 200 hours and the other after 600 hours. Given that the Per Unit Failure Rate is 0.000106383 , what is the Mean Time Between Failures? Select an answer and submit. For keyboard navigation, use the up/down arrow keys to select an answer. a 2,000 hours b 5,300 hours c 7,400 hours d 9,400 hours e 11,500 hours