Final answer:
The student's question pertains to understanding the probability of an event (John buying a car) given another event (Mary buying one), which falls under the category of conditional probability, a concept in probability theory used in market research inquiries.
Step-by-step explanation:
The question relates to the application of probability theory to understand consumer behavior, specifically the likelihood of one event (John purchasing a new car) given that another event has occurred (Mary purchasing one). This type of scenario falls under conditional probability, which is a part of probability theory. In the examples provided by the statistics material, we see similar concepts at play, such as calculating the proportion of households where women make the majority of purchasing decisions or finding the distribution of a random variable representing the number of dealerships a consumer needs to call before finding a specific car.
To address the initial student question, which seems like a market research inquiry, we would analyze data or conduct studies to determine the relationship between Mary's car purchase and the probability of John's subsequent purchase. If the data suggests a correlation, then one could apply statistical modeling to predict John's behavior based on Mary's action, and this would be carried out through probability calculations.