Final answer:
The ratio of sixth-grade students to seventh-grade students on the basketball team is 5:9.
Step-by-step explanation:
To find the ratio of sixth-grade students to seventh-grade students on the basketball team, we need to divide the number of sixth-grade students by the number of seventh-grade students. In this case, there are 5 sixth-grade students and 9 seventh-grade students. So the ratio is 5:9.