From: Correction of the significance level when attempting multiple transformations of an explanatory variable in generalized linear models
Number of transformations
c 1
c 2
c 3
…
c 9
1
q 1/2
2
q 1/3
q 2/3
3
q 1/4
q 2/4
q 3/4
⋮
9
q 1/10
q 2/10
q 9/10