Your question was answered in this Support thread started by you - Ticket ID: 400533. I'm sorry but I can not provide you an example with RadChart for WP7 at this moment. As my colleague Valentin said you will be able to use the earliest bits of the native WP7 chart soon so stay tuned.
the Telerik team
Registration for Q1 2011 What’s New Webinar Week is now open. Mark your calendar for the week starting March 21st and book your seat
for a walk through all the exciting stuff we ship with the new release!