Final answer:
The proportion of racial or ethnic groups in the United States is expected to change, not remain stable, with an increase in diversity due to immigration, differing birth rates, and the rising proportion of Hispanic Americans.
Step-by-step explanation:
The statement that the proportion of racial or ethnic groups in the United States is expected to be stable well into the next century is false. The racial and ethnic diversity of the U.S. population is set to increase significantly. According to the U.S. Bureau of the Census, while white Americans comprised 78% of the population in 2012, they are projected to make up 69% by 2060. Furthermore, the proportion of U.S. citizens of Hispanic background is predicted to rise substantially. Immigration and differing birth rates among races will continue to change the ethnic composition of the U.S.