Stats.Blue

Normal Probability Plot

Data
Data goes here (enter numbers in columns):


Sample Quantiles
Standard Normal Quantiles
Number of Data Points:
Regression Line:
Correlation:


The PPCC Test of Normality

Using the table below*, the user may objectively decide whether or not the data set entered above is normally distributed by performing a test of significance:

$H_0:$ Data is Normally Distributed
$H_a:$ Data is NOT Normally Distributed

where the correlation coefficient $r$ given above is the test statistic.

On the table, find the row corresponding to the size $n$ of your data set; if $r$ falls below the value indicated the at the desired level of significance ($\alpha$ is either 0.01, or 0.05), we reject $H_0$. Otherwise, we keep $H_0.$
				
	Number of Data Points n        0.01          0.05
				
3 0.8687 0.8790 4 0.8234 0.8666 5 0.8240 0.8786 6 0.8351 0.8880 7 0.8474 0.8970 8 0.8590 0.9043 9 0.8689 0.9115 10 0.8765 0.9173 11 0.8838 0.9223 12 0.8918 0.9267 13 0.8974 0.9310 14 0.9029 0.9343 15 0.9080 0.9376 16 0.9121 0.9405 17 0.9160 0.9433 18 0.9196 0.9452 19 0.9230 0.9479 20 0.9256 0.9498 21 0.9285 0.9515 22 0.9308 0.9535 23 0.9334 0.9548 24 0.9356 0.9564 25 0.9370 0.9575 26 0.9393 0.9590 27 0.9413 0.9600 28 0.9428 0.9615 29 0.9441 0.9622 30 0.9462 0.9634 31 0.9476 0.9644 32 0.9490 0.9652 33 0.9505 0.9661 34 0.9521 0.9671 35 0.9530 0.9678 36 0.9540 0.9686 37 0.9551 0.9693 38 0.9555 0.9700 39 0.9568 0.9704 40 0.9576 0.9712 41 0.9589 0.9719 42 0.9593 0.9723 43 0.9609 0.9730 44 0.9611 0.9734 45 0.9620 0.9739 46 0.9629 0.9744 47 0.9637 0.9748 48 0.9640 0.9753 49 0.9643 0.9758 50 0.9654 0.9761 55 0.9683 0.9781 60 0.9706 0.9797 65 0.9723 0.9809 70 0.9742 0.9822 75 0.9758 0.9831 80 0.9771 0.9841 85 0.9784 0.9850 90 0.9797 0.9857 95 0.9804 0.9864 100 0.9814 0.9869 110 0.9830 0.9881 120 0.9841 0.9889 130 0.9854 0.9897 140 0.9865 0.9904 150 0.9871 0.9909 160 0.9879 0.9915 170 0.9887 0.9919 180 0.9891 0.9923 190 0.9897 0.9927 200 0.9903 0.9930 210 0.9907 0.9933 220 0.9910 0.9936 230 0.9914 0.9939 240 0.9917 0.9941 250 0.9921 0.9943 260 0.9924 0.9945 270 0.9926 0.9947 280 0.9929 0.9949 290 0.9931 0.9951 300 0.9933 0.9952 310 0.9936 0.9954 320 0.9937 0.9955 330 0.9939 0.9956 340 0.9941 0.9957 350 0.9942 0.9958 360 0.9944 0.9959 370 0.9945 0.9960 380 0.9947 0.9961 390 0.9948 0.9962 400 0.9949 0.9963 410 0.9950 0.9964 420 0.9951 0.9965 430 0.9953 0.9966 440 0.9954 0.9966 450 0.9954 0.9967 460 0.9955 0.9968 470 0.9956 0.9968 480 0.9957 0.9969 490 0.9958 0.9969 500 0.9959 0.9970 525 0.9961 0.9972 550 0.9963 0.9973 575 0.9964 0.9974 600 0.9965 0.9975 625 0.9967 0.9976 650 0.9968 0.9977 675 0.9969 0.9977 700 0.9970 0.9978 725 0.9971 0.9979 750 0.9972 0.9980 775 0.9973 0.9980 800 0.9974 0.9981 825 0.9975 0.9981 850 0.9975 0.9982 875 0.9976 0.9982 900 0.9977 0.9983 925 0.9977 0.9983 950 0.9978 0.9984 975 0.9978 0.9984 1000 0.9979 0.9984
*Sources

The Probability Plot Correlation Coefficient Test for Normality. James J. Filliben. Technometrics, Vol. 17, No. 1. (Feb., 1975), pp. 111-117.

Critical Values of the Normal PPCC Distribution at nist.gov.