[II. The inverse problem:—given but a few of the errors to determine their centre and law, and thence to draw the above deductions. §§ 21–25.]
22, 23. The actual calculations are the same as before,
24. With the extra demand that we must determine how probable are the results.
25. Summary.
[III. Consideration of the same questions as applied to certain peculiar laws of error. §§ 26–37.]
26. (i) All errors equally probable.
27, 28. (ii) Certain peculiar laws of error.
29, 30. Further analysis of the reasons for taking averages.
31–35. Illustrative examples.
36, 37. Curves with double centre and absence of symmetry.
38, 39. Conclusion.