Communication is key in any position. Specifically, with a data analyst role, you will be expected to successfully present your findings and collaborate with the team. Assure them of your ability to communicate with an answer like this:

“My greatest communication strength would have to be my ability to relay information. I’m good at speaking in a simple, yet effective manner so that even people who aren’t familiar with the terms can grasp the overall concepts. I think communication is extremely valuable in a role like this, specifically when presenting my findings so that everyone understands the overall message.”