Sharp EL-5100 Instruction Manual page 56

Example: If we know a student's mark in mathematics, can we predict the mark in English?
The exam marks for five students chosen at random are given in the following table:
Student No. Mark in Math.
Mark in English
n X
Y
1
82
79
2
53 50
3
61
87
4
74 96
5
51
73
6
51
73
54