U.S. POPULATION GROWTH   			Write-Pair-Share

According to Census Bureau figures, the population of the United States grew at a rate of approximately 13.15% during the decade from 1990 to 2000, or an approximate annual growth rate of 1.243% (0.01243 as a decimal); the population in 2000 was counted at 281,421,906.  

Note:  The annual growth rate (1.243%) is less than one-tenth of the ten-year growth rate (1.315%) due to the effect of compound growth.  In each of the ten individual years, the population increases; when the same annual growth rate is applied to successive years, the results are increasingly larger, i.e., the numerical growth is not evenly distributed throughout the ten-year period.  When successively applied in each of the ten years from 1990-1999, the annual growth rate of 1.243% produces the same effect as the overall ten-year growth rate of 13.15% when applied once to the population in 1990.  In other words, from 1990 to 2000 (additional decimal places included for accuracy):

Assignment: 
Based on the figures above, construct an exponential population growth model, P(t) =  · , where represents the U.S. population in 2000,  a represents the annual growth factor (not the annual growth rate), and t represents the number of elapsed years since 2000.  

Please answer the following four questions:  
In #1-3, if the current growth rate continues unchanged, what will the population of the U.S. be in the indicated years?

#	Year	
1.	2050	
2.	2100	
3.	2150	

4.	Discuss with your partner how the U.S. population growth might affect your future in practical terms.  Record the major implications and consequences that you find and submit a brief report (including your answers for questions #1-3 above).

Note:  Population data obtained from: http://www.censusscope.org/us/chart_popl.html 

Note: To raise a number to a power on most scientific calculators (including the one that is accessible via your computer's Start/Programs/Accessories/Calculator/View/Scientific menu), first enter the base number, then press the button labeled y x (sometimes labeled), then enter the exponent value, and press the "=" key.  For example, to raise 5 to the 3rd power (i.e., 5 cubed, or 53), enter the base value of 5, press the yx button (or thebutton), enter the exponent value of 3, and press the "=" key. 
If you have a graphing calculator, replace the y x above with the ”^” key.