Please answer.

Determine whether the distribution represents a probability distribution. Explain your answer. (5 points each) X 1 5 8 7 P(X) 1. X 2 4 8 P(X) X P(X) 3. X 8 12 15 17 P(X] X 1 3 5 7 P(X) 0.35 0.25 0.22 0.12