Final answer:
The probability of saving money without a subscription cannot be determined from the given information, as it lacks sufficient context and data regarding movie-watching habits and the cost metrics of subscription versus non-subscription services.
Step-by-step explanation:
The provided information seems to be missing crucial context that would allow for a calculation of the probability of saving money without a subscription. Probability typically involves a well-defined scenario with outcomes that can be clearly enumerated or described statistically. The question regarding the probability of saving money without a subscription appears to be trying to address a real-world financial decision rather than a mathematical probability problem. It is unclear what events or statistics the probability should be based on without additional information on movie-watching habits, subscription costs, and the cost of individual movies outside the subscription.
In a case where you know the average number of movies watched and the costs with and without the subscription, you could calculate the expected value or use a cost-benefit analysis to determine which option saves money in the long run. However, the student's question, as stated, does not provide enough data for such a calculation. Thus, the question is not answerable without additional context about the family's movie-watching habits and the financial aspects of the subscription service.