CompTIA Strata *In the event that you fail your first (1st) attempt to pass any CompTIA certification examination, CompTIA does not require any waiting period between the first (1st) and second (2nd) attempt to pass such examination.
See normal distribution for the bell curve in statistics. The Bell Curve is a controversial, best-selling 1994 book by Richard J. Herrnstein and Charles Murray exploring the role of intelligence in American life. The authors became notorious for the book's discussion of race and intelligence in Chapters 13 and 14.
Figure 1 illustrates two especially important characters of a curve that has several names: the normal curve, the bell curve, and the Gaussian curve. Six sigma in the laboratory--part two For a normal curve, two-thirds of the values (approximately 67%) fall within a range plus or minus one standard deviation around the mean.