Final answer:
A p.i (probability index) of less than 1.0 indicates that the probability of an event occurring is less than 50%. Thus the correct option is (1).
Explanation:
The probability index (p.i) is a measure used to assess the likelihood of an event occurring. It is calculated by dividing the probability of the event by the probability of its complement (the event not occurring). A p.i of less than 1.0 indicates that the probability of the event is less than the probability of its complement. In other words, the event is less likely to occur than not to occur. For example, if the probability of an event is 0.4 and the probability of its complement is 0.6, then the p.i would be 0.4/0.6, which is less than 1.0. This suggests that the event has a lower chance of occurring than not occurring. Thus the correct option is (1).
In contrast, a p.i of greater than 1.0 indicates that the probability of the event is greater than the probability of its complement, implying that the event is more likely to occur than not to occur. A p.i of exactly 1.0 indicates that the probability of the event and its complement are equal, meaning that the event is equally likely to occur or not to occur. When calculating a p.i, it's essential to ensure that both probabilities add up to 1, as this represents a complete set of possible outcomes.
If either probability is greater than 1, it indicates an error in calculation or a misunderstanding of the problem's nature. In summary, a p.i of less than 1.0 signifies a lower likelihood of an event occurring compared to its complement's likelihood, while a p.i greater than 1.0 denotes a higher likelihood, and a p.i equal to 1.0 implies an equal likelihood for both events and their complements.