Table 1: The number of students in each combination of the number of tests passed in two related university courses in actuarial science.

First course Total
0 1 2 3 4
Second course 0 0 0 2 2 0 4
1 0 0 2 2 1 5
2 0 0 2 4 6 12
3 0 0 0 5 26 31
Total 0 0 6 13 33 52