Page 65 - Petrology of Sedimentary Rocks

Extended values for t for d.f>30, based on Fisher and Yates, Statistical Tables, with
linear extrapolations,

P = lo-4, t = 3.9 P = 10-12 , t = 7.2 (trillion)

= 10-5, t = 4.4 = IO-15, t = 8.2 (quadrillion)

= 10-6 , t = 4.9 (million) = 10-18, t = 9.3 (quintillion)

= 10-7 , t = 5.3 = 10-21 , t = 10.3 (sextillion)

= 10-8, t = 5.7 = 10-24, t = I I .3 (septillion)

9
= IO- , t = 6.1 (billion) = 10-27 , t = 12.3 (octillion)

Abridged Table of X2

counts
when
This table
----- can be used only -------- the data is in the form of discrete -- of individuals.
Freedom F P 1
Degrees of 0 .,50 0.20 0. IO 0.05 0.02 0.01 0.001

I 0.45 1.65 2.71 3.84 5.41 6.64 10.83

2 1.39 3.26 4.61 5.99 7.82 9.21 13.82

3 2.37 4.65 6.25 7.82 9.84 Il.3 16.2

4 3.36 5.91 7.7 9.4 II.6 13.2 18.4

6 5.35 8.60 10.6 12.5 15.0’ 16.8 22.4

8 7.34 Il.0 13.3 15.5 18. I 20.0 26.1

IO 9.34 13.4 15.9 18.3 21.1 23.2 29.5

I5 14.3 19.3 22.3 25.0 28.2 30.5 37.7

20 19.3 25.1 28.4 31.4 35.0 37.5 45.3

25 24.3 30.7 34.3 37.6 41.5 44.3 52.6

30 29.3 36.2 40.2 43.7 47.9 50.8 59.7

Enter the table with the proper degrees of freedom and read right until you reach
the (interpolated) value of X2 you obtained by calculation. Then read up to the top of

the table the corresponding P. Example: for 8 d.f., X2 = 14. I; therefore P = about .08,
i.e., there are 8 chances in 100 that the differences are to chance. As a general rule, if

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