Construct a normal probability plot for the fatigue-crack propagation data given in Exercise 39 (Chapter 1). Does it appear plausible that propagation life has a normal distribution? Explain.
Exercise 39 The propagation of fatigue cracks in various aircraft parts has been the subject of extensive study in recent years.
The accompanying data consists of propagation lives (flight hours/104) to reach a given crack size in fastener h oles intended for use in military aircraft ("Statistical Crack Propagation in Fastener Holes Under Spectrum Loading," J. Aircraft, 1983: 1028-1032):
a. Compute and compare the values of the sample mean and median.
b. By how much could the largest sample observation be decreased without affecting the value of the median