In a notched tensile fatigue test on a titanium specimen, the expected number of cycles to first acoustic emission (used to indicate crack initiation) is u = 28,000, and the standard deviation of the...

Extracted text: In a notched tensile fatigue test on a titanium specimen, the expected number of cycles to first acoustic emission (used to indicate crack initiation) is u = 28,000, and the standard deviation of the number of cycles is o = 4000. Let X1, X2, .... X25 be a random sample of size 25, where each X, is the number of cycles on a different randomly selected specimen. Then the expected value of the -Select--- number of cycles until first emission is E(X) = µ = 28,000, and the expected total number of cycles for the specimens is E(T,) = nu = 25(28,000) = 700,000. The standard deviations of X and T, are o, = Vno = V25(4000) = ( If the sample size increases to n = 100, E(X) is unchanged but o =