Final answer:
The exact percentage of women 75 years and older who live alone cannot be determined from the provided information, which discusses broader demographic trends related to the aging population in the U.S.
Step-by-step explanation:
The percentage of women 75 years and older who live alone is not provided directly in the information given. However, based on U.S. Census Bureau statistics and the discussion on the aging population, it can be inferred that a significant portion of older women live alone, especially given that women generally have a longer life expectancy than men. It is important to note that the detailed information shared speaks to the broad demographic trends of aging in the United States and the growing number of the elderly population, but it does not specify the exact percentage of women 75 and older living alone. Since the precise answer to this question is not available in the provided reference data, the answer would be 'Cannot be determined' without additional specific data on living arrangements.