Final answer:
Without specific data for Rwanda, we can't provide the exact number of female mobile phone users. However, a referenced study on smartphone usage indicated that a significant number of women sampled did use smartphones. Further, increased mobile phone access in Sub-Saharan Africa suggests that women's phone usage is substantial.
Step-by-step explanation:
To determine the proportion of female mobile phone users in Rwanda, let's reference a research study regarding smartphone use. The study found that out of 1,304 women sampled, 404 used smartphones. In contrast, of the 973 men sampled, 379 used smartphones.
Since the question pertains to Rwanda, specifics about the country's demographics or mobile phone usage are not provided. However, we can infer from the global study that women's phone usage in general can be significant. Specific data on Rwanda would be required to provide an exact figure for the number of female mobile phone users in the country.
It's also noteworthy that across Sub-Saharan Africa, there has been a substantial increase in mobile phone access, making technology more available to women as well. Educational disparities, such as those indicated by the World Bank with lower literacy rates among females compared to males in certain African countries, might influence mobile phone usage and should be considered in further detailed studies.