Final answer:
Unclear specifics make it impossible to accurately determine the probability of project completion in 13 months. Different mathematical and statistical methods are needed for such estimates.
Step-by-step explanation:
The question seems to be asking about the probability of completing a project in 13 months. However, various percentages and mathematical equations related to different scenarios have been mentioned. The context of these percentages and how they apply to the project's completion is unclear without additional information. To calculate the probability of completing the project in a specific timeframe, one would typically use a specific statistical or project management methodology such as PERT (Program Evaluation Review Technique) or CPM (Critical Path Method) which incorporate known data about the tasks involved and their durations. The given examples do not directly provide a method for determining this probability.