- Email: [email protected]
Appendix B Statistical tables
APPENDIX B
Statistical tables
This appendix contains tables of the t - and the F-distributions. These tables are used to assess the significance of estimated parameters obtained by experiments. Two examples to illustrate how the tables can be used are given below.
B.1
Table B1, t-distribution
The t-distribution gives the critical t-values. These values are used to compare estimated parameters to estimates of its standard deviation. An example will illustrate how this can be accomplished: An experimental variable is judged to have a significant influence on the response only if it has an influence above the noise level of the random experimental error variations. The influence of the variable is measured by its response surface coefficient b,. An estimate of its standard error can be obtained from an estimate of the standard deviation of the experimental error. Assume that you have run experiments by a factorial design (with NF runs) with a view to assessing the significance of the experimental variables from estimates, b,, of the coefficients in a linear response surface model. Assume also that you have made No repeated runs of one experiment to obtain an estimate of the experimental error standard deviation. From the average response, Y, in repeated runs, an estimate of the experimental error standard deviation, So, with ( N o - 1) degrees of freedom is obtained as /
No t',..
~/ E,--I~,~ -2
(N0-i)
9) 2
(B.1)
The standard error, se, of the estimated coefficient is then obtained by dividing the experimental error standard deviation by NF, see Chapter 3.
se = so/V/~e.
(B.2)
t=b,/s~
(B.3)
Determine the t-ratio
551
552
STATISTICAL TABLES
For bi to be significantly above the noise level, the value of t should be outside the range +tcrit given in Table B1. Table B1 has two entries: The column heads specify the value of a / 2 , where c~ is the significance level, i.e. the probability that the experimental t-value by pure chance exceeds the critical t-value. It is common to use a significance level of a = 0.05 = (5)%. This corresponds to the column heading 0.025. The rows of the table specify the number of degrees of freedom of the estimate of the standard deviation. A ( 1 0 0 - a ) . 100% confidence interval for the "true" value,/~i, of the response surface parameter is obtained as ~i = bi - tcritSe <_ ~i <_ bi + tcritSe
(B.4)
B.2 Tables B2-B4, F-distribution F-distribution gives critical F-values. These values are used to compare estimates of variances to each other. An example is shown on how the F-distribution can be used to assess whether a response surface model can be assumed to give an adequate description of the variation of the response, or if it shows a significant lack of fit. There will always be residuals, ei, between the experimentally observed response in experiment i and the corresponding value predicted by the model. If the model is adequate, these residuals should be nothing but manifestations of the experimental error. From the sum of squared residuals, ~ e~, we can compute the residual mean square, R M S , as 1
RMS
-- N -
p
ei'
where N is the number of experiments used to fit the model, and p is the number of parameters in the model. If the model is adequate R M S would be an estimate, s~, of the experimental error variance with nl = (N - p) degrees of freedom. Another, and independent, estimate of the experimental error variance, s 2, with n2 = (No- 1) degrees of freedom may be obtained by No repeated runs of a given experiment. These two estimates of the experimental error variance have been obtained with different degrees of freedom. Even if the model is adequate, they may seem to be different. To determine whether or not they are statistically significant, we can use the F distribution. If the model is adequate, the F-ratio F = s~ s~'
(B.6)
should not exceed the critical F-value for nl and n2 degrees of freedom in Tables B 2 B4. These tables show the critical F-values for the significance level ~ - 10, 5, and 1 %. There are two entries in the tables, corresponding to the degrees of freedom of the estimated variances.
B.3.
B.3
SOURCES
553
Sources
9 Table B1 has been taken from E.S. Pearson and H.O. Hartley (Eds.) Biometrika Tables .for Statisticians, Vol. 1, Cambridge University Press 1958. 9 Tables B1 B3 have been taken from M. Merrington and C.M. Thompson, Tables of percentage points of the inverted beta (F) distribution, Biometrika 33 (1943) 73. The tables have been reproduced with permission of the publishers.
554
STATISTICAL TABLES
Table BI: t-Distribution. Probability points for the significance level ~ and n degrees of freedom. Degrees of freedom 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 40 60 120 c~
Tail area probability a/2 0.05 0.025 0.005 6.314 12.706 63.657 2.920 4.303 9.925 2.353 3.182 5.841 2.132 2.776 4.604 2.015 2.571 4.032 1.943 2.447 3.702 1.895 2.365 3.499 1.860 2.306 3.355 1.833 2.262 3.250 1.812 2.228 3.169 1.796 2.201 3.106 1.782 2.179 3.055 1 . 7 7 1 2.160 3.012 1 . 7 6 1 2.145 2.977 1.753 2.131 2.947 1.746 2.120 2.921 1.740 2.110 2.898 1.734 2.101 2.878 1.729 2.093 2.861 1.725 2.086 2.845 1.721 2.080 2.831 1.717 2.074 2.819 1.714 2.069 2.807 1 . 7 1 1 2.064 2.797 1.708 2.060 2.787 1.706 2.056 2.779 1.703 2.052 2.771 1 . 7 0 1 2.048 2.763 1.699 2.045 2.756 1.697 2.042 2.750 1.684 2.021 2.704 1.671 2.000 2.660 1.658 1.980 2.617 1.645 1.960 2.576
B.3. SOURCES
555
556
STATISTICAL TABLES
Table B2: F-Distribution. Critical F = s~/s~ ratios, upper 10 ~o points. The degrees of freedom are n i for s~ and n: for s~. nl
n2 1 1 39.86 2 8.53 3 5.54 4 4.54 5 4.06 6 3.78 7 3.59 8 3.46 9 3.36 10 3.29 11 3.23 12 3.18 13 3.14 14 3.10 15 3.07 16 3.05 17 3.03 18 3.01 19 2.99 20 2.97 21 2.96 22 2.95 23 2.94 24 2.93 25 2.92 26 2.91 27 2.90 28 2.89 29 2.89 30 2.88 40 2.84 60 2.79 120 2.75 C~ 2.71
2 49.50 9.00 5.46 4.32 3.78 3.46 3.26 3.11 3.01 2.92 2.86 2.81 2.76 2.73 2.70 2.67 2.64 2.62 2.61 2.59 2.57 2.56 2.55 2.54 2.53 2.52 2.51 2.50 2.50 2.49 2.44 2.39 2.35 2.30
3 53.59 9.16 5.39 4.19 3.62 3.29 3.07 2.92 2.81 2.73 2.66 2.61 2.56 2.52 2.49 2.46 2.44 2.42 2.40 2.38 2.36 2.35 2.34 2.33 2.32 2.31 2.30 2.29 2.28 2.28 2.23 2.18 2.13 2.08
4 53.83 9.24 5.34 4.11 3.52 3.18 2.96 2.81 2.69 2.61 2.54 2.48 2.43 2.39 2.36 2.33 2.31 2.29 2.27 2.25 2.23 2.22 2.21 2.19 2.18 2.17 2.17 2.16 2.15 2.14 2.09 2.04 1.99 1.94
5 6 7 8 9 10 58.24 58.20 58.91 59.44 59.86 60.19 9.29 9.33 9.35 9.37 9.38 9.39 5.31 5.28 5.27 5.25 5.24 5.23 4.05 4.01 3.98 3.95 3.94 3.92 3.45 3.40 3.37 3.34 3.32 3.30 3.11 3.05 3.01 2.98 2.96 2.94 2.88 2.83 2.78 2.75 2.72 2.80 2.73 2.67 2.62 2.59 2.56 2.54 2.61 2.55 2.51 2.47 2.44 2.42 2.52 2.46 2.41 2.38 2.35 2.32 2.45 2.39 2.34 2.30 2.27 2.25 2.39 2.33 2.28 2.24 2.21 2.19 2.35 2.28 2.23 2.20 2.16 2.14 2.31 2.24 2.19 2.15 2.12 2.10 2.27 2.21 2.16 2.12 2.09 2.06 2.24 2.18 2.13 2.09 2.06 2.03 2.22 2.15 2.10 2.06 2.03 2.00 2.20 2.13 2.08 2.04 2.00 1.98 2.18 2.11 2.06 2.02 1.98 1.96 2.16 2.09 2.04 2.00 1.96 1.94 2.14 2.08 2.02 1.98 1.95 1.92 2.13 2.06 2.01 1.97 1.93 1.90 2.11 2.05 1.99 1.95 1.92 1.89 2.10 2.04 1.98 1.94 1.91 1.88 2.09 2.02 1.97 1.93 1.89 1.87 2.08 2.01 1.96 1.92 1.88 1.86 2.07 2.00 1.95 1.91 1.87 1.85 2.06 2.00 1.94 1.90 1.87 1.84 2.06 1.99 1.93 1.89 1.86 1.83 2.05 1.98 1.83 1.88 1.85 1.82 2.00 1.93 1.87 1.83 1.79 1.76 1.95 1.87 1.82 1.77 1.74 1.71 1.90 1.82 1.77 1.72 1.68 1.65 1.85 1.77 1.72 1.67 1.63 1.60
B.3.
SOURCES nl n2 12 1 60.71 2 9.41 3 5.22 4 3.90 5 3.27 6 2.90 7 2.67 8 2.50 9 2.38 10 2.28 11 2.21 12 2.15 13 2.10 14 2.05 15 2.02 16 1.99 17 1.96 18 1.93 19 1.91 20 1.89 21 1.87 22 1.86 23 1.84 24 1.83 25 1.82 26 1.81 27 1.80 28 1.79 29 1.78 30 1.77 40 1.71 60 1.66 120 1.60 C~ 1.55
557
15 61.22 9.42 5.20 3.87 3.24 2.87 2.63 2.46 2.34 2.24 2.17 2.10 2.05 2.01 1.97 1.94 1.91 1.89 1.86 1.84 1.83 1.81 1.80 1.78 1.77 1.76 1.75 1.74 1.73 1.72 1.66 1.60 1.55 1.49
20 61.74 9.44 5.18 3.84 3.21 2.84 2.59 2.42 2.30 2.20 2.12 2.06 2.01 1.96 1.92 1.89 1.86 1.84 1.81 1.79 1.78 1.76 1.74 1.73 1.72 1.71 1.70 1.69 1.68 1.67 1.61 1.54 1.48 1.42
24 62.00 9.45 5.18 3.83 3.19 2.82 2.58 2.40 2.28 2.18 2.10 2.04 1.98 1.94 1.90 1.87 1.84 1.81 1.79 1.77 1.75 1.73 1.72 1.70 1.69 1.68 1.67 1.66 1.65 1.64 1.57 1.51 1.45 1.38
30 62.26 9.46 5.27 3.82 3.17 2.80 2.56 2.38 2.25 2.16 2.08 2.01 1.96 1.91 1.87 1.84 1.81 1.78 1.76 1.74 1.72 1.70 1.69 1.67 1.66 1.65 1.64 1.63 1.62 1.61 1.54 1.48 1.41 1.34
40 62.53 9.47 5.16 3.80 3.16 2.78 2.54 2.36 2.23 2.13 2.05 1.99 1.93 1.89 1.85 1.81 1.78 1.75 1.73 1.71 1.69 1.67 1.66 1.64 1.63 1.61 1.60 1.59 1.58 1.57 1.51 1.44 1.37 1.30
60 62.79 9.47 5.15. 3.79 3.14 2.76 2.51 2.34 2.21 2.11 2.03 1.96 1.90 1.86 1.82 1.78 1.75 1.72 1.70 1.68 1.66 1.64 1.62 1.61 1.59 1.58 1.57 1.56 1.55 1.54 1.47 1.40 1.32 1.24
120 63.06 9.48 5.14 3.78 3.12 2.74 2.49 2.32 2.18 2.08 2.00 1.93 1.88 1.83 1.79 1.75 1.72 1.69 1.67 1.64 1.62 1.60 1.59 1.57 1.56 1.54 1.53 1.52 1.51 1.50 1.42 1.35 1.26 1.17
oo 63.33 9.49 5.13 3.76 3.10 2.72 2.47 2.29 2.16 2.06 1.97 1.90 1.85 1.80 1.76 1.72 1.69 1.66 1.63 1.61 1.59 1.57 1.55 1.53 1.52 1.50 1.49 1.48 1.47 1.46 1.38 1.29 1.19 1.00
558
STATISTICAL TABLES
Table B2: F-Distribution. Critical F = s2/s 2 ratios, upper 5 ~o points. The degrees o/ freedom are n l for s 2 and n2 for s 2. nl
n2 1 2 3 4 5 6 7 8 9 I0 II 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 40 60 120 00
1 161.4 18.51 10.13 7.71 6.61 5.99 5.59 5.32 5.12 4.96 4.84 4.75 4.68 4.60 4.54 4.49 4.45 4.41 4.38 4.35 4.32 4.30 4.28 4.26 4.24 4.23 4.21 4.20 4.18 4.17 4.08 4.00 3.92 3.84
2 199.5 19.00 9.55 6.94 5.79 5.14 4.74 4.46 4.26 4.10 3.98 3.89 3.81 3.74 3.68 3.63 3.59 3.55 3.52 3.49 3.47 3.44 3.42 3.40 3.39 3.37 3.35 3.34 3.33 3.32 3.23 3.15 3.07 3.00
3 215.7 19.16 9.28 6.59 5.41 4.76 4.35 4.07 3.86 3.71 3.59 3.49 3.41 3.34 3.29 3.24 3.20 3.16 3.13 3.10 3.07 3.05 3.03 3.01 2.99 2.98 2.96 2.95 2.93 2.92 2.84 2.76 2.68 2.60
4 224.6 19.25 9.12 6.39 5.19 4.53 4.12 3.84 3.63 3.48 3.36 3.26 3.18 3.11 3.06 3.01 2.96 2.93 2.90 2.87 2.84 2.82 2.80 2.78 2.76 2.74 2.73 2.71 2.70 2.69 2.61 2.53 2.45 2.37
5 230.2 19.30 9.01 6.26 5.05 4.39 3.97 3.69 3.48 3.33 3.20 3.11 3.03 2.96 2.90 2.85 2.81 2.77 2.74 2.71 2.68 2.66 2.64 2.62 2.60 2.59 2.57 2.56 2.55 2.53 2.45 2.37 2.29 2.21
6 234.0 19.33 8.94 6.16 4.95 4.28 3.87 3.58 3.37 3.22 3.09 3.00 2.92 2.85 2.79 2.74 2.70 2.66 2.63 2.60 2.57 2.55 2.53 2.51 2.49 2.47 2.46 2.45 2.43 2.42 2.34 2.25 2.17 2.10
7 236.8 19.35 8.89 6.09 4.88 4.21 3.79 3.50 3.39 3.14 3.01 2.91 2.83 2.76 2.71 2.66 2.61 2.58 2.54 2.51 2.49 2.46 2.44 2.42 2.40 2.39 2.37 2.36 2.35 2.33 2.25 2.17 2.09 2.01
8 9 10 238.9 240.5 241.9 19.37 19.38 19.40 8.85 8.81 8.79 6.04 6.00 5.96 4.82 4.77 4.74 4.15 4.10 4.06 3.73 3.68 3.64 3.44 3.39 3.35 3.23 3.18 3.14 3.07 3.02 2.98 2.95 2.90 2.85 2.85 2.80 2.75 2.77 2.71 2.67 2.70 2.65 2.60 2.64 2.59 2.54 2.59 2.54 2.49 2.55 2.49 2.45 2.51 2.46 2.41 2.48 2.42 2.38 2.45 2.39 2.35 2.42 2.37 2.32 2.40 2.34 2.30 2.37 2.32 2.27 2.36 2.30 2.25 2.34 2.28 2.24 2.32 2.27 2.22 2.31 2.25 2.20 2.29 2.24 2.19 2.28 2.22 2.18 2.27 2.21 2.16 2.18 2.12 2.08 2.10 2.04 1.99 2.02 1.96 1.91 1.94 1.88 1.83
B.3.
SOURCES
559
nl
n2 12 15 20 24 30 40 60 120 co 1 243.9 245.9 248.0 249.1 250.1 251.1 252.2 253.3 254.3 2 19.41 19.43 19.45 19.45 19.46 19.47 19.48 19.49 19.50 3 8.74 8.70 8.66 8.64 8.62 8.59 8.57 8.55 8.43 4 5.91 5.86 5.80 5.77 5.75 5.72 5.69 5.66 5.63 5 4.68 4.62 4.56 4.53 4.50 4.46 4.43 4.40 4.36 6 4.00 3.94 3.87 3.84 3.81 3.77 3.74 3.70 3.67 7 3.57 3.51 3.45 3.41 3.38 3.34 3.30 3.27 3.23 8 3.28 3.22 3.15 3.12 3.08 3.04 3.01 2.97 2.93 9 3.07 3.01 2.94 2.90 2.86 2.83 2.79 2.75 2.71 10 2.91 2.85 2.77 2.74 2.70 2.66 2.62 2.58 2.54 11 2.79 2.72 2.65 2 . 6 1 2.58 2.53 2.49 2.45 2.40 12 2.69 2.62 2.54 2.51 2.48 2.43 2.38 2.34 2.30 13 2.60 2.53 2.46 2.42 2.38 2.34 2.30 2.25 2.21 14 2.53 2.46 2.39 2.35 2.31 2.27 2.22 2.18 2.13 15 2.48 2.40 2.33 2.29 2.25 2.20 2.16 2.11 2.07 16 2.42 2.35 2.28 2.24 2.19 2.15 2.11 2.06 2.01 17 2.38 2.31 2.23 2.19 2.15 2.10 2.06 2.01 1.96 18 2.34 2.27 2.19 2.15 2.11 2.06 2.02 1.97 1.92 19 2.31 2.23 2.16 2.11 2.07 2.03 1.98 1.93 1.88 20 2.28 2.20 2.12 2.08 2.04 1.99 1.95 1.90 1.84 21 2.25 2.18 2.10 2.05 2.01 1.96 1.92 1.87 1.81 22 2.23 2.15 2.07 2.03 1.98 1.94 1.89 1.84 1.78 23 2.20 2.13 2.05 2.01 1.96 1.91 1.86 1.81 1.76 24 2.18 2.11 2.03 1.98 1.94 1.89 1.84 1.79 1.73 25 2.16 2.09 2.01 1.96 1.92 1.87 1.82 1.77 1.71 26 2.15 2.07 1.99 1.95 1.90 1.85 1.80 1.75 1.69 27 2.13 2.06 1.97 1.93 1.88 1.84 1.79 1.73 1.67 28 2.12 2.04 1.96 1.91 1.87 1.82 1.77 1.71 1.65 29 2.10 2.03 1.94 1.90 1.85 1.81 1.75 1.70 1.64 30 2.09 2.01 1.93 1.89 1.84 1.79 1.74 1.68 1.62 40 2.00 1.92 1.84 1.79 1.74 1.69 1.64 1.58 1.51 60 1.92 1.84 1.75 1.70 1.65 1.59 1.53 1.48 1.39 120 1.83 1.75 1.66 1.61 1.55 1.50 1.43 1.35 1.25 CO 1.75 1.67 1.57 1.52 1.46 1.39 1.32 1.22 1.00
560
STATISTICAL TABLES
Table B2: F-Distribution. Critical F = s 2l / s 2 ratios, upper 1 ~ points. The degrees of freedom are nl for s 2 and n2 for s 2 (Multiply entries marked with * by 100). nl
n2 1 2 3 4 5 6 7 8 9 10 1 40.52, 49.99, 54.03, 56.25, 57.64, 58.59, 59.28, 59.82, 69.22, 60.56, 2 98.50 99.00 99.17 99.25 99.30 99.33 99.36 99.37 99.39 99.40 3 34.12 30.82 29.46 28.71 28.24 27.91 27.67 27.49 27.35 27.23 4 21.20 18.00 16.69 15.98 15.52 1 5 . 2 1 14.98 14.80 14.66 14.55 5 16.26 13.27 12.06 11.29 10.97 10.67 10.46 10.29 10.16 10.05 6 13.75 10.92 9.78 9.15 8.75 8.47 8.26 8.10 7.98 7.87 7 12.25 9.55 8.45 7.85 7.46 7.19 6.99 6.84 6.72 6.62 8 11.26 8.65 7.59 7.01 6.63 6.37 6.18 6.03 5.91 5.81 9 10.56 8.02 6.99 6.42 6.06 5.80 6.61 5.47 5.35 5.26 10 10.04 7.56 6.55 5.99 5.64 5.39 5.20 5.06 4.94 4.85 11 9.65 7.21 6.22 5.67 5.32 5.07 4.89 4.74 4.63 4.54 12 9.33 6.93 5.95 5.41 5.06 4.82 4.64 4.50 4.39 4.30 13 9.07 6.70 5.74 5.21 4.86 4.62 4.44 4.30 4.19 4.10 14 8.86 6.51 5.56 5.04 4.69 4.46 4.28 4.14 4.03 3.94 15 8.68 6.36 5.42 4.89 4.56 4.32 4.14 4.00 3.89 3.80 16 8.53 6.23 5.29 4.77 4.44 4.20 4.03 3.89 3.78 3.69 17 8.40 6.11 5.18 4.67 4.34 4.10 3.93 3.79 3.68 3.59 18 8.29 6.01 5.09 4.58 4.25 4.01 3.84 3.71 3.60 3.51 19 8.18 5.93 5.01 4.50 4.17 3.94 3.77 3.63 3.52 3.43 20 8.10 5.85 4.94 4.43 4.10 3.87 3.70 3.56 3.46 3.37 21 8.02 5.78 4.87 4.37 4.04 3.81 3.64 3.51 3.40 3.31 22 7.95 5.72 4.82 4.31 3.99 3.76 3.59 3.45 3.35 3.26 23 7.88 5.66 4.76 4.26 3.94 3.71 3.54 3.41 3.30 3.21 24 7.82 5.61 4.72 4.22 3.90 3.67 3.50 3.36 3.26 3.17 25 7.77 5.57 4.68 4.18 3.85 3.63 3.46 3.32 3.22 3.13 26 7.72 5.53 4.64 4.14 3.82 3.59 3.42 3.29 3.18 3.09 27 7.68 5.49 4.60 4.11 3.78 3.56 3.39 3.26 3.15 3.06 28 7.64 5.45 4.57 4.07 3.75 3.53 3.36 3.23 3.12 3.03 29 7.60 5.42 4.54 4.04 3.73 3.50 3.33 3.20 3.09 3.00 30 7.56 5.39 4.51 4.02 3.70 3.47 3.30 3.17 3.07 2.98 40 7.31 5.18 4.31 3.83 3.51 3.29 3.12 2.99 2.89 2.80 60 7.08 4.98 4.13 3.65 3.34 3.12 2.95 2.82 2.72 2.63 120 6.85 4.79 3.95 3.48 3.17 2.96 2.79 2.66 2.56 2.47 r 6.63 4.61 3.78 3.32 3.02 2.80 2.64 2.51 2.41 2.32
B.3.
SOURCES
561
nl
n2 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 40 60 120 c~
12 61.06, 99.42 27.05 14.37 9.89 7.72 6.47 5.67 5.11 4.71 4.40 4.16 3.96 3.80 3.67 3.55 3.46 3.37 3.30 3.23 3.17 3.12 3.07 3.03 2.99 2.96 2.93 2.90 2.87 2.84 2.66 2.50 2.34 2.18
15 61.57, 99.43 26.87 14.20 9.72 7.56 6.31 5.52 4.96 4.56 4.25 4.01 3.82 3.66 3.52 3.41 3.31 3.23 3.15 3.09 3.03 2.98 2.93 2.89 2.85 2.81 2.78 2.75 2.73 2.70 2.52 2.35 2.19 2.04
20 62.09, 99.45 26.69 14.02 9.55 7.40 6.16 5.36 4.81 4.41 4.10 3.86 3.66 3.51 3.37 3.26 3.16 3.08 3.00 2.94 2.88 2.83 2.78 2.74 2.70 2.66 2.63 2.60 2.57 2.55 2.37 2.20 2.03 1.88
24 62.35* 99.46 26.60 13.93 9.47 7.31 6.07 5.28 4.73 4.33 4.02 3.78 3.59 3.43 3.29 3.18 3.08 3.00 2.92 2.86 2.80 2.75 2.70 2.66 2.62 2.58 2.55 2.52 2.49 2.47 2.29 2.12 1.95 1.79
3O 40 62.61, 62.87, 99.47 99.47 26.50 26.41 13.84 13.75 9.38 9.29 7.23 7.14 5.99 5.91 5.20 5.12 4.65 4.57 4.25 4.17 3.94 3.86 3.70 3.62 3.51 3.43 3.35 3.27 3.21 3.13 3.10 3.02 3.00 2.92 2.92 2.84 2.84 2.76 2.78 2.69 2.72 2.64 2.68 2.58 2.62 2.54 2.58 2.49 2.54 2.45 2.50 2.42 2.47 2.38 2.44 2.35 2.41 2.33 2.39 2.30 2.20 2.11 2.03 1.94 1.86 1.76 1.70 1.59
60 63.13, 99.48 26.32 13.65 9.20 7.06 5.82 5.03 4.48 4.08 3.78 3.54 3.34 3.18 3.05 2.93 2.83 2.75 2.67 2.61 2.55 2.50 2.45 2.40 2.36 2.33 2.28 2.26 2.23 2.21 2.02 1.84 1.66 1.47
120 63.39, 99.49 26.22 13.56 9.11 6.97 5.74 4.95 4.40 4.00 3.69 3.45 3.25 3.09 2.96 2.84 2.75 2.66 2.58 2.52 2.46 2.40 2.35 2.31 2.27 2.23 2.20 2.17 2.14 2.11 1.92 1.73 1.53 1.32
O~D
63.66, 99.50 .... 26.13 13.46 9.02 6.88 5.65 4.86 4.31 3.91 3.60 3.36 3.17 3.00 2.87 2.75 2.65 2.57 2.49 2.42 2.36 2.31 2.26 2.21 2.17 2.13 2.10 2.06 2.03 2.01 1.80 1.60 1.38 1.00
Statistical tables
This appendix contains tables of the t - and the F-distributions. These tables are used to assess the significance of estimated parameters obtained by experiments. Two examples to illustrate how the tables can be used are given below.
B.1
Table B1, t-distribution
The t-distribution gives the critical t-values. These values are used to compare estimated parameters to estimates of its standard deviation. An example will illustrate how this can be accomplished: An experimental variable is judged to have a significant influence on the response only if it has an influence above the noise level of the random experimental error variations. The influence of the variable is measured by its response surface coefficient b,. An estimate of its standard error can be obtained from an estimate of the standard deviation of the experimental error. Assume that you have run experiments by a factorial design (with NF runs) with a view to assessing the significance of the experimental variables from estimates, b,, of the coefficients in a linear response surface model. Assume also that you have made No repeated runs of one experiment to obtain an estimate of the experimental error standard deviation. From the average response, Y, in repeated runs, an estimate of the experimental error standard deviation, So, with ( N o - 1) degrees of freedom is obtained as /
No t',..
~/ E,--I~,~ -2
(N0-i)
9) 2
(B.1)
The standard error, se, of the estimated coefficient is then obtained by dividing the experimental error standard deviation by NF, see Chapter 3.
se = so/V/~e.
(B.2)
t=b,/s~
(B.3)
Determine the t-ratio
551
552
STATISTICAL TABLES
For bi to be significantly above the noise level, the value of t should be outside the range +tcrit given in Table B1. Table B1 has two entries: The column heads specify the value of a / 2 , where c~ is the significance level, i.e. the probability that the experimental t-value by pure chance exceeds the critical t-value. It is common to use a significance level of a = 0.05 = (5)%. This corresponds to the column heading 0.025. The rows of the table specify the number of degrees of freedom of the estimate of the standard deviation. A ( 1 0 0 - a ) . 100% confidence interval for the "true" value,/~i, of the response surface parameter is obtained as ~i = bi - tcritSe <_ ~i <_ bi + tcritSe
(B.4)
B.2 Tables B2-B4, F-distribution F-distribution gives critical F-values. These values are used to compare estimates of variances to each other. An example is shown on how the F-distribution can be used to assess whether a response surface model can be assumed to give an adequate description of the variation of the response, or if it shows a significant lack of fit. There will always be residuals, ei, between the experimentally observed response in experiment i and the corresponding value predicted by the model. If the model is adequate, these residuals should be nothing but manifestations of the experimental error. From the sum of squared residuals, ~ e~, we can compute the residual mean square, R M S , as 1
RMS
-- N -
p
ei'
where N is the number of experiments used to fit the model, and p is the number of parameters in the model. If the model is adequate R M S would be an estimate, s~, of the experimental error variance with nl = (N - p) degrees of freedom. Another, and independent, estimate of the experimental error variance, s 2, with n2 = (No- 1) degrees of freedom may be obtained by No repeated runs of a given experiment. These two estimates of the experimental error variance have been obtained with different degrees of freedom. Even if the model is adequate, they may seem to be different. To determine whether or not they are statistically significant, we can use the F distribution. If the model is adequate, the F-ratio F = s~ s~'
(B.6)
should not exceed the critical F-value for nl and n2 degrees of freedom in Tables B 2 B4. These tables show the critical F-values for the significance level ~ - 10, 5, and 1 %. There are two entries in the tables, corresponding to the degrees of freedom of the estimated variances.
B.3.
B.3
SOURCES
553
Sources
9 Table B1 has been taken from E.S. Pearson and H.O. Hartley (Eds.) Biometrika Tables .for Statisticians, Vol. 1, Cambridge University Press 1958. 9 Tables B1 B3 have been taken from M. Merrington and C.M. Thompson, Tables of percentage points of the inverted beta (F) distribution, Biometrika 33 (1943) 73. The tables have been reproduced with permission of the publishers.
554
STATISTICAL TABLES
Table BI: t-Distribution. Probability points for the significance level ~ and n degrees of freedom. Degrees of freedom 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 40 60 120 c~
Tail area probability a/2 0.05 0.025 0.005 6.314 12.706 63.657 2.920 4.303 9.925 2.353 3.182 5.841 2.132 2.776 4.604 2.015 2.571 4.032 1.943 2.447 3.702 1.895 2.365 3.499 1.860 2.306 3.355 1.833 2.262 3.250 1.812 2.228 3.169 1.796 2.201 3.106 1.782 2.179 3.055 1 . 7 7 1 2.160 3.012 1 . 7 6 1 2.145 2.977 1.753 2.131 2.947 1.746 2.120 2.921 1.740 2.110 2.898 1.734 2.101 2.878 1.729 2.093 2.861 1.725 2.086 2.845 1.721 2.080 2.831 1.717 2.074 2.819 1.714 2.069 2.807 1 . 7 1 1 2.064 2.797 1.708 2.060 2.787 1.706 2.056 2.779 1.703 2.052 2.771 1 . 7 0 1 2.048 2.763 1.699 2.045 2.756 1.697 2.042 2.750 1.684 2.021 2.704 1.671 2.000 2.660 1.658 1.980 2.617 1.645 1.960 2.576
B.3. SOURCES
555
556
STATISTICAL TABLES
Table B2: F-Distribution. Critical F = s~/s~ ratios, upper 10 ~o points. The degrees of freedom are n i for s~ and n: for s~. nl
n2 1 1 39.86 2 8.53 3 5.54 4 4.54 5 4.06 6 3.78 7 3.59 8 3.46 9 3.36 10 3.29 11 3.23 12 3.18 13 3.14 14 3.10 15 3.07 16 3.05 17 3.03 18 3.01 19 2.99 20 2.97 21 2.96 22 2.95 23 2.94 24 2.93 25 2.92 26 2.91 27 2.90 28 2.89 29 2.89 30 2.88 40 2.84 60 2.79 120 2.75 C~ 2.71
2 49.50 9.00 5.46 4.32 3.78 3.46 3.26 3.11 3.01 2.92 2.86 2.81 2.76 2.73 2.70 2.67 2.64 2.62 2.61 2.59 2.57 2.56 2.55 2.54 2.53 2.52 2.51 2.50 2.50 2.49 2.44 2.39 2.35 2.30
3 53.59 9.16 5.39 4.19 3.62 3.29 3.07 2.92 2.81 2.73 2.66 2.61 2.56 2.52 2.49 2.46 2.44 2.42 2.40 2.38 2.36 2.35 2.34 2.33 2.32 2.31 2.30 2.29 2.28 2.28 2.23 2.18 2.13 2.08
4 53.83 9.24 5.34 4.11 3.52 3.18 2.96 2.81 2.69 2.61 2.54 2.48 2.43 2.39 2.36 2.33 2.31 2.29 2.27 2.25 2.23 2.22 2.21 2.19 2.18 2.17 2.17 2.16 2.15 2.14 2.09 2.04 1.99 1.94
5 6 7 8 9 10 58.24 58.20 58.91 59.44 59.86 60.19 9.29 9.33 9.35 9.37 9.38 9.39 5.31 5.28 5.27 5.25 5.24 5.23 4.05 4.01 3.98 3.95 3.94 3.92 3.45 3.40 3.37 3.34 3.32 3.30 3.11 3.05 3.01 2.98 2.96 2.94 2.88 2.83 2.78 2.75 2.72 2.80 2.73 2.67 2.62 2.59 2.56 2.54 2.61 2.55 2.51 2.47 2.44 2.42 2.52 2.46 2.41 2.38 2.35 2.32 2.45 2.39 2.34 2.30 2.27 2.25 2.39 2.33 2.28 2.24 2.21 2.19 2.35 2.28 2.23 2.20 2.16 2.14 2.31 2.24 2.19 2.15 2.12 2.10 2.27 2.21 2.16 2.12 2.09 2.06 2.24 2.18 2.13 2.09 2.06 2.03 2.22 2.15 2.10 2.06 2.03 2.00 2.20 2.13 2.08 2.04 2.00 1.98 2.18 2.11 2.06 2.02 1.98 1.96 2.16 2.09 2.04 2.00 1.96 1.94 2.14 2.08 2.02 1.98 1.95 1.92 2.13 2.06 2.01 1.97 1.93 1.90 2.11 2.05 1.99 1.95 1.92 1.89 2.10 2.04 1.98 1.94 1.91 1.88 2.09 2.02 1.97 1.93 1.89 1.87 2.08 2.01 1.96 1.92 1.88 1.86 2.07 2.00 1.95 1.91 1.87 1.85 2.06 2.00 1.94 1.90 1.87 1.84 2.06 1.99 1.93 1.89 1.86 1.83 2.05 1.98 1.83 1.88 1.85 1.82 2.00 1.93 1.87 1.83 1.79 1.76 1.95 1.87 1.82 1.77 1.74 1.71 1.90 1.82 1.77 1.72 1.68 1.65 1.85 1.77 1.72 1.67 1.63 1.60
B.3.
SOURCES nl n2 12 1 60.71 2 9.41 3 5.22 4 3.90 5 3.27 6 2.90 7 2.67 8 2.50 9 2.38 10 2.28 11 2.21 12 2.15 13 2.10 14 2.05 15 2.02 16 1.99 17 1.96 18 1.93 19 1.91 20 1.89 21 1.87 22 1.86 23 1.84 24 1.83 25 1.82 26 1.81 27 1.80 28 1.79 29 1.78 30 1.77 40 1.71 60 1.66 120 1.60 C~ 1.55
557
15 61.22 9.42 5.20 3.87 3.24 2.87 2.63 2.46 2.34 2.24 2.17 2.10 2.05 2.01 1.97 1.94 1.91 1.89 1.86 1.84 1.83 1.81 1.80 1.78 1.77 1.76 1.75 1.74 1.73 1.72 1.66 1.60 1.55 1.49
20 61.74 9.44 5.18 3.84 3.21 2.84 2.59 2.42 2.30 2.20 2.12 2.06 2.01 1.96 1.92 1.89 1.86 1.84 1.81 1.79 1.78 1.76 1.74 1.73 1.72 1.71 1.70 1.69 1.68 1.67 1.61 1.54 1.48 1.42
24 62.00 9.45 5.18 3.83 3.19 2.82 2.58 2.40 2.28 2.18 2.10 2.04 1.98 1.94 1.90 1.87 1.84 1.81 1.79 1.77 1.75 1.73 1.72 1.70 1.69 1.68 1.67 1.66 1.65 1.64 1.57 1.51 1.45 1.38
30 62.26 9.46 5.27 3.82 3.17 2.80 2.56 2.38 2.25 2.16 2.08 2.01 1.96 1.91 1.87 1.84 1.81 1.78 1.76 1.74 1.72 1.70 1.69 1.67 1.66 1.65 1.64 1.63 1.62 1.61 1.54 1.48 1.41 1.34
40 62.53 9.47 5.16 3.80 3.16 2.78 2.54 2.36 2.23 2.13 2.05 1.99 1.93 1.89 1.85 1.81 1.78 1.75 1.73 1.71 1.69 1.67 1.66 1.64 1.63 1.61 1.60 1.59 1.58 1.57 1.51 1.44 1.37 1.30
60 62.79 9.47 5.15. 3.79 3.14 2.76 2.51 2.34 2.21 2.11 2.03 1.96 1.90 1.86 1.82 1.78 1.75 1.72 1.70 1.68 1.66 1.64 1.62 1.61 1.59 1.58 1.57 1.56 1.55 1.54 1.47 1.40 1.32 1.24
120 63.06 9.48 5.14 3.78 3.12 2.74 2.49 2.32 2.18 2.08 2.00 1.93 1.88 1.83 1.79 1.75 1.72 1.69 1.67 1.64 1.62 1.60 1.59 1.57 1.56 1.54 1.53 1.52 1.51 1.50 1.42 1.35 1.26 1.17
oo 63.33 9.49 5.13 3.76 3.10 2.72 2.47 2.29 2.16 2.06 1.97 1.90 1.85 1.80 1.76 1.72 1.69 1.66 1.63 1.61 1.59 1.57 1.55 1.53 1.52 1.50 1.49 1.48 1.47 1.46 1.38 1.29 1.19 1.00
558
STATISTICAL TABLES
Table B2: F-Distribution. Critical F = s2/s 2 ratios, upper 5 ~o points. The degrees o/ freedom are n l for s 2 and n2 for s 2. nl
n2 1 2 3 4 5 6 7 8 9 I0 II 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 40 60 120 00
1 161.4 18.51 10.13 7.71 6.61 5.99 5.59 5.32 5.12 4.96 4.84 4.75 4.68 4.60 4.54 4.49 4.45 4.41 4.38 4.35 4.32 4.30 4.28 4.26 4.24 4.23 4.21 4.20 4.18 4.17 4.08 4.00 3.92 3.84
2 199.5 19.00 9.55 6.94 5.79 5.14 4.74 4.46 4.26 4.10 3.98 3.89 3.81 3.74 3.68 3.63 3.59 3.55 3.52 3.49 3.47 3.44 3.42 3.40 3.39 3.37 3.35 3.34 3.33 3.32 3.23 3.15 3.07 3.00
3 215.7 19.16 9.28 6.59 5.41 4.76 4.35 4.07 3.86 3.71 3.59 3.49 3.41 3.34 3.29 3.24 3.20 3.16 3.13 3.10 3.07 3.05 3.03 3.01 2.99 2.98 2.96 2.95 2.93 2.92 2.84 2.76 2.68 2.60
4 224.6 19.25 9.12 6.39 5.19 4.53 4.12 3.84 3.63 3.48 3.36 3.26 3.18 3.11 3.06 3.01 2.96 2.93 2.90 2.87 2.84 2.82 2.80 2.78 2.76 2.74 2.73 2.71 2.70 2.69 2.61 2.53 2.45 2.37
5 230.2 19.30 9.01 6.26 5.05 4.39 3.97 3.69 3.48 3.33 3.20 3.11 3.03 2.96 2.90 2.85 2.81 2.77 2.74 2.71 2.68 2.66 2.64 2.62 2.60 2.59 2.57 2.56 2.55 2.53 2.45 2.37 2.29 2.21
6 234.0 19.33 8.94 6.16 4.95 4.28 3.87 3.58 3.37 3.22 3.09 3.00 2.92 2.85 2.79 2.74 2.70 2.66 2.63 2.60 2.57 2.55 2.53 2.51 2.49 2.47 2.46 2.45 2.43 2.42 2.34 2.25 2.17 2.10
7 236.8 19.35 8.89 6.09 4.88 4.21 3.79 3.50 3.39 3.14 3.01 2.91 2.83 2.76 2.71 2.66 2.61 2.58 2.54 2.51 2.49 2.46 2.44 2.42 2.40 2.39 2.37 2.36 2.35 2.33 2.25 2.17 2.09 2.01
8 9 10 238.9 240.5 241.9 19.37 19.38 19.40 8.85 8.81 8.79 6.04 6.00 5.96 4.82 4.77 4.74 4.15 4.10 4.06 3.73 3.68 3.64 3.44 3.39 3.35 3.23 3.18 3.14 3.07 3.02 2.98 2.95 2.90 2.85 2.85 2.80 2.75 2.77 2.71 2.67 2.70 2.65 2.60 2.64 2.59 2.54 2.59 2.54 2.49 2.55 2.49 2.45 2.51 2.46 2.41 2.48 2.42 2.38 2.45 2.39 2.35 2.42 2.37 2.32 2.40 2.34 2.30 2.37 2.32 2.27 2.36 2.30 2.25 2.34 2.28 2.24 2.32 2.27 2.22 2.31 2.25 2.20 2.29 2.24 2.19 2.28 2.22 2.18 2.27 2.21 2.16 2.18 2.12 2.08 2.10 2.04 1.99 2.02 1.96 1.91 1.94 1.88 1.83
B.3.
SOURCES
559
nl
n2 12 15 20 24 30 40 60 120 co 1 243.9 245.9 248.0 249.1 250.1 251.1 252.2 253.3 254.3 2 19.41 19.43 19.45 19.45 19.46 19.47 19.48 19.49 19.50 3 8.74 8.70 8.66 8.64 8.62 8.59 8.57 8.55 8.43 4 5.91 5.86 5.80 5.77 5.75 5.72 5.69 5.66 5.63 5 4.68 4.62 4.56 4.53 4.50 4.46 4.43 4.40 4.36 6 4.00 3.94 3.87 3.84 3.81 3.77 3.74 3.70 3.67 7 3.57 3.51 3.45 3.41 3.38 3.34 3.30 3.27 3.23 8 3.28 3.22 3.15 3.12 3.08 3.04 3.01 2.97 2.93 9 3.07 3.01 2.94 2.90 2.86 2.83 2.79 2.75 2.71 10 2.91 2.85 2.77 2.74 2.70 2.66 2.62 2.58 2.54 11 2.79 2.72 2.65 2 . 6 1 2.58 2.53 2.49 2.45 2.40 12 2.69 2.62 2.54 2.51 2.48 2.43 2.38 2.34 2.30 13 2.60 2.53 2.46 2.42 2.38 2.34 2.30 2.25 2.21 14 2.53 2.46 2.39 2.35 2.31 2.27 2.22 2.18 2.13 15 2.48 2.40 2.33 2.29 2.25 2.20 2.16 2.11 2.07 16 2.42 2.35 2.28 2.24 2.19 2.15 2.11 2.06 2.01 17 2.38 2.31 2.23 2.19 2.15 2.10 2.06 2.01 1.96 18 2.34 2.27 2.19 2.15 2.11 2.06 2.02 1.97 1.92 19 2.31 2.23 2.16 2.11 2.07 2.03 1.98 1.93 1.88 20 2.28 2.20 2.12 2.08 2.04 1.99 1.95 1.90 1.84 21 2.25 2.18 2.10 2.05 2.01 1.96 1.92 1.87 1.81 22 2.23 2.15 2.07 2.03 1.98 1.94 1.89 1.84 1.78 23 2.20 2.13 2.05 2.01 1.96 1.91 1.86 1.81 1.76 24 2.18 2.11 2.03 1.98 1.94 1.89 1.84 1.79 1.73 25 2.16 2.09 2.01 1.96 1.92 1.87 1.82 1.77 1.71 26 2.15 2.07 1.99 1.95 1.90 1.85 1.80 1.75 1.69 27 2.13 2.06 1.97 1.93 1.88 1.84 1.79 1.73 1.67 28 2.12 2.04 1.96 1.91 1.87 1.82 1.77 1.71 1.65 29 2.10 2.03 1.94 1.90 1.85 1.81 1.75 1.70 1.64 30 2.09 2.01 1.93 1.89 1.84 1.79 1.74 1.68 1.62 40 2.00 1.92 1.84 1.79 1.74 1.69 1.64 1.58 1.51 60 1.92 1.84 1.75 1.70 1.65 1.59 1.53 1.48 1.39 120 1.83 1.75 1.66 1.61 1.55 1.50 1.43 1.35 1.25 CO 1.75 1.67 1.57 1.52 1.46 1.39 1.32 1.22 1.00
560
STATISTICAL TABLES
Table B2: F-Distribution. Critical F = s 2l / s 2 ratios, upper 1 ~ points. The degrees of freedom are nl for s 2 and n2 for s 2 (Multiply entries marked with * by 100). nl
n2 1 2 3 4 5 6 7 8 9 10 1 40.52, 49.99, 54.03, 56.25, 57.64, 58.59, 59.28, 59.82, 69.22, 60.56, 2 98.50 99.00 99.17 99.25 99.30 99.33 99.36 99.37 99.39 99.40 3 34.12 30.82 29.46 28.71 28.24 27.91 27.67 27.49 27.35 27.23 4 21.20 18.00 16.69 15.98 15.52 1 5 . 2 1 14.98 14.80 14.66 14.55 5 16.26 13.27 12.06 11.29 10.97 10.67 10.46 10.29 10.16 10.05 6 13.75 10.92 9.78 9.15 8.75 8.47 8.26 8.10 7.98 7.87 7 12.25 9.55 8.45 7.85 7.46 7.19 6.99 6.84 6.72 6.62 8 11.26 8.65 7.59 7.01 6.63 6.37 6.18 6.03 5.91 5.81 9 10.56 8.02 6.99 6.42 6.06 5.80 6.61 5.47 5.35 5.26 10 10.04 7.56 6.55 5.99 5.64 5.39 5.20 5.06 4.94 4.85 11 9.65 7.21 6.22 5.67 5.32 5.07 4.89 4.74 4.63 4.54 12 9.33 6.93 5.95 5.41 5.06 4.82 4.64 4.50 4.39 4.30 13 9.07 6.70 5.74 5.21 4.86 4.62 4.44 4.30 4.19 4.10 14 8.86 6.51 5.56 5.04 4.69 4.46 4.28 4.14 4.03 3.94 15 8.68 6.36 5.42 4.89 4.56 4.32 4.14 4.00 3.89 3.80 16 8.53 6.23 5.29 4.77 4.44 4.20 4.03 3.89 3.78 3.69 17 8.40 6.11 5.18 4.67 4.34 4.10 3.93 3.79 3.68 3.59 18 8.29 6.01 5.09 4.58 4.25 4.01 3.84 3.71 3.60 3.51 19 8.18 5.93 5.01 4.50 4.17 3.94 3.77 3.63 3.52 3.43 20 8.10 5.85 4.94 4.43 4.10 3.87 3.70 3.56 3.46 3.37 21 8.02 5.78 4.87 4.37 4.04 3.81 3.64 3.51 3.40 3.31 22 7.95 5.72 4.82 4.31 3.99 3.76 3.59 3.45 3.35 3.26 23 7.88 5.66 4.76 4.26 3.94 3.71 3.54 3.41 3.30 3.21 24 7.82 5.61 4.72 4.22 3.90 3.67 3.50 3.36 3.26 3.17 25 7.77 5.57 4.68 4.18 3.85 3.63 3.46 3.32 3.22 3.13 26 7.72 5.53 4.64 4.14 3.82 3.59 3.42 3.29 3.18 3.09 27 7.68 5.49 4.60 4.11 3.78 3.56 3.39 3.26 3.15 3.06 28 7.64 5.45 4.57 4.07 3.75 3.53 3.36 3.23 3.12 3.03 29 7.60 5.42 4.54 4.04 3.73 3.50 3.33 3.20 3.09 3.00 30 7.56 5.39 4.51 4.02 3.70 3.47 3.30 3.17 3.07 2.98 40 7.31 5.18 4.31 3.83 3.51 3.29 3.12 2.99 2.89 2.80 60 7.08 4.98 4.13 3.65 3.34 3.12 2.95 2.82 2.72 2.63 120 6.85 4.79 3.95 3.48 3.17 2.96 2.79 2.66 2.56 2.47 r 6.63 4.61 3.78 3.32 3.02 2.80 2.64 2.51 2.41 2.32
B.3.
SOURCES
561
nl
n2 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 40 60 120 c~
12 61.06, 99.42 27.05 14.37 9.89 7.72 6.47 5.67 5.11 4.71 4.40 4.16 3.96 3.80 3.67 3.55 3.46 3.37 3.30 3.23 3.17 3.12 3.07 3.03 2.99 2.96 2.93 2.90 2.87 2.84 2.66 2.50 2.34 2.18
15 61.57, 99.43 26.87 14.20 9.72 7.56 6.31 5.52 4.96 4.56 4.25 4.01 3.82 3.66 3.52 3.41 3.31 3.23 3.15 3.09 3.03 2.98 2.93 2.89 2.85 2.81 2.78 2.75 2.73 2.70 2.52 2.35 2.19 2.04
20 62.09, 99.45 26.69 14.02 9.55 7.40 6.16 5.36 4.81 4.41 4.10 3.86 3.66 3.51 3.37 3.26 3.16 3.08 3.00 2.94 2.88 2.83 2.78 2.74 2.70 2.66 2.63 2.60 2.57 2.55 2.37 2.20 2.03 1.88
24 62.35* 99.46 26.60 13.93 9.47 7.31 6.07 5.28 4.73 4.33 4.02 3.78 3.59 3.43 3.29 3.18 3.08 3.00 2.92 2.86 2.80 2.75 2.70 2.66 2.62 2.58 2.55 2.52 2.49 2.47 2.29 2.12 1.95 1.79
3O 40 62.61, 62.87, 99.47 99.47 26.50 26.41 13.84 13.75 9.38 9.29 7.23 7.14 5.99 5.91 5.20 5.12 4.65 4.57 4.25 4.17 3.94 3.86 3.70 3.62 3.51 3.43 3.35 3.27 3.21 3.13 3.10 3.02 3.00 2.92 2.92 2.84 2.84 2.76 2.78 2.69 2.72 2.64 2.68 2.58 2.62 2.54 2.58 2.49 2.54 2.45 2.50 2.42 2.47 2.38 2.44 2.35 2.41 2.33 2.39 2.30 2.20 2.11 2.03 1.94 1.86 1.76 1.70 1.59
60 63.13, 99.48 26.32 13.65 9.20 7.06 5.82 5.03 4.48 4.08 3.78 3.54 3.34 3.18 3.05 2.93 2.83 2.75 2.67 2.61 2.55 2.50 2.45 2.40 2.36 2.33 2.28 2.26 2.23 2.21 2.02 1.84 1.66 1.47
120 63.39, 99.49 26.22 13.56 9.11 6.97 5.74 4.95 4.40 4.00 3.69 3.45 3.25 3.09 2.96 2.84 2.75 2.66 2.58 2.52 2.46 2.40 2.35 2.31 2.27 2.23 2.20 2.17 2.14 2.11 1.92 1.73 1.53 1.32
O~D
63.66, 99.50 .... 26.13 13.46 9.02 6.88 5.65 4.86 4.31 3.91 3.60 3.36 3.17 3.00 2.87 2.75 2.65 2.57 2.49 2.42 2.36 2.31 2.26 2.21 2.17 2.13 2.10 2.06 2.03 2.01 1.80 1.60 1.38 1.00