How many of the world's population are women?

Answer: half

Answer: It's usually slightly greater than half. Though it fluctuates from year to year and from race to race, the typical average ratio of men to women in the world is usually 10 to 9 (10 women for every 9 men)

This is due to two factors:
1. Female birth rate is slightly higher than male baby birthrate by a small percentage.

2. Females on average live a few years longer, so the longer you track any given population, the more females are left alive in any given population center over time.