The space shuttle employs epoxy spherical vessels in an environment of sustained pressure. A study of the lifetimes of epoxy strands subjected to sustained stress was conducted. The data giving the lifetimes (in hours) of 100 strands tested at a prescribed level of stress is given in the following table.
.18 3.1 4.2 6.0 7.5 8.2 8.5 10.3 10.6 24.2
29.6 31.7 41.9 44.1 49.5 50.1 59.7 61.7 64.4 69.7
70.0 77.8 80.5 82.3 83.5 84.2 87.1 87.3 93.2 103.4
104.6 105.5 108.8 112.6 116.8 118.0 122.3 123.5 124.4 125.4
129.5 130.4 131.6 132.8 133.8 137.0 140.2 140.9 148.5 149.2
152.2 152.9 157.7 160.0 163.6 166.9 170.5 174.9 177.7 179.2
183.6 183.8 194.3 195.1 195.3 202.6 220.0 221.3 227.2 251.0
266.5 267.9 269.2 270.4 272.5 285.9 292.6 295.1 301.1 304.3
316.8 329.8 334.1 346.2 351.2 353.3 369.3 372.3 381.3 393.5
451.3 461.5 574.2 656.3 663.0 669.8 739.7 759.6 894.7 974.9
Estimate with 99% certainty the time, L:95, such that at least 95% of epoxy strands under the prescribed stress would have lifetimes greater than L:95.
Predict with 95% certainty the lifetime of a strand subjected to the prescribed stress.