3. In 2010, the U.S. population was about 309 million. The overall birth rate was 13.0 births per 1000, and the overall death rate was 7.4 deaths per 1000.

a) Approximately how many births were there in the United States?

b) About how many deaths were there in the United States?

c) Based on births and deaths alone (not counting immigration or emigration), about how much did the U.S. population increase during 2010?

d) Suppose that during 2010 the U.S. population actually increase by 3.5 million. Based on this fact and your results from part (c), estimate how many people immigrated to the United States. What proportion of the overall population growth was due to immigration?

4. The table shows the U.S. population and the number of Americans over age 65 at 10-year intervals since 1940 (about when the Social Security program was created).

YEAR

1940

1950

1960

1970

1980

1990

2000

2010

U.S.

Population

(millions)

132

151

179

203

227

249

281

309

Americans over age 65 (millions)

9.0

12.7

17.2

20.9

26.1

31.9

34.9

40.4

a) What is the percentage increase in the U.S. population between 1940 and 2010?

b) What is the percentage increase in the over-65 population between 1940 and 2010?

c) In 2010, there were approximately 165 million Americans of working age (25-65). Estimate (Assume of this population is working), the number of people who were actually working and contributing to Social Security in 2010. Compare this number to the over-65 population.

d) How do these results affect the future of programs such as Social Security and Medicare?