Final answer:
The number of owners who describe their pets as family members depends on individual preferences and cultural differences. It is difficult to determine the exact number without more specific data.
Step-by-step explanation:
Out of the 71 million families that own one pet, the number of owners who describe their pets as family members depends on individual preferences and cultural differences. In the United States, there is a range of opinions on what constitutes a family, with some people considering pets as family members and others not. According to a survey conducted by the University of Indiana, nearly all participants agreed that a husband, wife, and children constitute a family, but the numbers drop for less traditional structures like unmarried couples with or without children. So, it is difficult to determine the exact number of owners who describe their pets as family members without more specific data.