Final answer:
The question cannot be accurately answered as it lacks the specific hearing threshold data for the 64-year-old male and the 74-year-old female required to calculate the ratio of minimum sound intensities heard by them.
Step-by-step explanation:
The question concerning the ratio of minimum sound intensities heard by different age groups does not have sufficient information provided to answer it directly. Normally, the ratios of intensities of two sounds can be determined if the difference in decibels (dB) between the two thresholds is known. However, in this scenario, we do not have the specific hearing thresholds for the 64-year-old male and the 74-year-old female. Furthermore, hearing ability can vary significantly among individuals, and age alone is not sufficient to determine these intensities without additional hearing loss information.
For example, question 71 suggests that the ratio of intensities of two sounds of identical frequency, where the first is just barely discernible as louder than the second, does not provide a direct calculation but rather implies the concept of a just noticeable difference in sound intensities. Similarly, questions that refer to hearing loss in dB at specific frequencies (for instance, question 69 and 70), indicate that a calculation could be performed if the specific dB thresholds were given.
In the absence of clear hearing threshold data for the 64-year-old male and the 74-year-old female, we cannot determine a specific ratio for the sound intensities required for each to hear the sounds. Thus, the question cannot be answered accurately with the information provided.