ILLUSTRATIONS 



1 Curve of probability density function of a gaussian random 



variable. . .-page 6 



2 Block diagram of Probability Density Analyzer system. . . 7 

 3-4 Selected probability density curves, compared with a 



normal curve. . . 12-13 

 5-6 Examples of PD curves obtained by use of overlay method. . . 15-1 7 



7 Curve obtained with Probability Density Analyzer. . . 23 



8 Normalized cumulative sums of tabulated values. . . 25 



9 Curves with positive and negative skewness, computed 



with Edgeworth's series. . . 26 



10 Curves with positive and negative kurtosis. . . 2 7 



11-12 Cumulative probability of noise samples shown in figures 

 3 and 4. . .28-29 

 13 Experimental PD curve of random noise showing skewness, 



calculated by Edgeworth's series. . .34 

 Al Theoretical and experimental PD curves of square wave 



and sine wave. „ .41 

 Bl Number of times random noise goes into an interval 



about x = for PD of 0. 4, vs. cutoff frequency of 

 low-pass filter. „ .4 5 



