Question
Which of the following cannot be valid assignment of probability for elements or outcomes of sample space $s = W_1, W_2,W_{3,} W_4, W_5, W_6, W_7$.
| Elementary events: | $W_1$ | $W_2$ | $W_3$ | $W_4$ | $W_5$ | $W_6$ | $W_7$ |
| $\frac{1}{14}$ | $\frac{2}{14}$ | $\frac{3}{14}$ | $\frac{4}{14}$ | $\frac{5}{14}$ | $\frac{6}{14}$ | $\frac{15}{14}$ |
