Activity Three:

Purpose:

1. to compare population data as represented on an ordinary line graph and a semilogrithmic graph.

2. to relate population growth to historical events and sociological factors.

3. to calculate the density and the rate of change of a population.

4. to predict the future size of a population based on past trends as shown on graphs.

Procedure A:

1. Graph the US population on regular graph paper.

2. Graph the same data on semi-logrithmic graph paper. Extend the line to the year 2010.

Discussion Questions:

1. Compare your two graphs. What can you tell on the regular graph that is not shown as well on the semi-logrithmic graph paper? What can you tell on the semi-logrithmic graph that it not shown as well on the regular graph?

2. What factors account for the slower rise in population around the 1930's? What factors account for the faster growth of the population in the mid -to late 1940's?

3. What do predict the U.S. population to be in the year 2010? What factors have to stay the same for this prediction to become true?
4. Compare your ordenary line graph of the US population with the world population. Explain similarities and difficulties.
5. Identify three surges of growth.
6. What are the limiting factors that act on the US. population on your city or county?
7. What are possible sources of error int the data from the US. Census from 1790 to the present? What percent % errors would you estimate there might be in the census?

Procedure B:

1. Determine the population density of Los Angeles County. Remember density is equal to the number of individuals in a population divided by the space they occcupy or D= N/T.
   Population Growth in Los Angeles County by Single Year

2. Determine the rate of change of the population of Los Angeles County for the years 1930 to 1990. Rate is thechange in density divided by the change in time or

   R=	D1-D2
   T1-T2

Discussion Questions:

1. How does the density of Los Angeles County in 1980 compare with the U.S. population density as a whole?

2. Is the rate of change of Los Angeles County increasing faster or slower than the U.S. population? How can you compare these two rates of change more accurately?