Rising health care costs are a growing concern for everyone in the United States. With U.S. Centers

Question:

Rising health care costs are a growing concern for everyone in the United States. With U.S. Centers for Medicare and Medicaid Services data from 2006 and projected to 2021, U.S. per capita health care costs can be described by
y = 20.61x2 - 116.4x + 7406
where x is the number of years past 2000. Use this equation to find, to the nearest dollar, the average rate of change of U.S. per capita health care costs from 2010 to 2015 and from 2015 to 2020?