Which one of the following relationships is most likely to be stochastic rather than deterministic?

a) The relationship between the number of hours LEAP tutors work in one pay period and the size of their paycheck for that period.
b) The relationship between the number of boxes of Girl Scout cookies sold and the total revenue generated from the sales of Girl Scout cookies.
c) The relationship between the number of hours students study and their GPAs.
d) The relationship between the ticket revenue from a concert and the number of tickets sold.

Ans: c) The relationship between the number of hours students study and their GPAs.