Code of Federal Regulations > Title 10 > Chapter II > Part 429 > Subpart B > Appendix Appendix A - Appendix A to Subpart B of Part 429—Student's t-Distribution Values for Certification Testing

Regulations last checked for updates: Feb 22, 2025

Title 10 - Energy last revised: Feb 20, 2025

Appendix Appendix A - Appendix A to Subpart B of Part 429—Student's t-Distribution Values for Certification Testing

Figure 1—t-Distribution Values for Certification Testing

[One-Sided]

Degrees of freedom (from Appendix A)	Confidence Interval
Degrees of freedom (from Appendix A)	90%	95%	97.5%	99%
1	3.078	6.314	12.71	31.82
2	1.886	2.920	4.303	6.965
3	1.638	2.353	3.182	4.541
4	1.533	2.132	2.776	3.747
5	1.476	2.015	2.571	3.365
6	1.440	1.943	2.447	3.143
7	1.415	1.895	2.365	2.998
8	1.397	1.860	2.306	2.896
9	1.383	1.833	2.262	2.821
10	1.372	1.812	2.228	2.764
11	1.363	1.796	2.201	2.718
12	1.356	1.782	2.179	2.681
13	1.350	1.771	2.160	2.650
14	1.345	1.761	2.145	2.624
15	1.341	1.753	2.131	2.602
16	1.337	1.746	2.120	2.583
17	1.333	1.740	2.110	2.567
18	1.330	1.734	2.101	2.552
19	1.328	1.729	2.093	2.539
20	1.325	1.725	2.086	2.528

[76 FR 12451, Mar. 7, 2011; 76 FR 24780, May 2, 2011]

authority: 42 U.S.C. 6291-6317; 28 U.S.C. 2461 note

source: 76 FR 12451, Mar. 7, 2011, unless otherwise noted.