Do you have experience speaking in front of a large audience? What size groups are you comfortable speaking in front of?

"Yes I do, but it has been fairly limited over the last 12 years of my career as a registered nurse. I am an active member of my church and have given the guest sermon many times in front of a congregation of about 150 people. While at first I was a bit nervous, I have become much more confident over time. As a community health nurse here, I would feel very comfortable and confident in the subject matter and would be able to generate fruitful conversations with the attendees of presentations and forums."

While public speaking has always been a top fear of most people, you need to stress to your interviewer that you are a confident and effective public speaker. If you have specific examples of diverse groups you've presented to, use those examples to show your interviewer that you can work with a wide variety of people.