Which of the following cannot be the probability of an event? (iii) 37% (iv) -2.4

(iii) As 0 ≤ 37 % = (37/100) ≤ 1

Thus, 37 % can be a probability of an event.

(iv) As -2.4 < 0

Thus, -2.4 cannot be a probability of an event.