Final answer:
In a Punnett square, the percentage of offspring that will be female is 50%.
Step-by-step explanation:
In a Punnett square, the possible combinations of alleles from the parents are represented. In the given Punnett square, there are 4 possible outcomes: XX, XY, XX, and XY. The two combinations that result in a female offspring are XX and XX. So, out of the 4 possibilities, 2 represent female offspring. Therefore, the percentage of offspring that will be female is 50%.