Section P.3▪Exponents and Scientific Notation

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In Exercises 77-86, write each number in scientific notation.
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In Exercises 87-106, perform the indicated computations. Write the answers in scientific notation. If necessary, round the decimal factor in your scientific notation answer to two decimal places.
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Practice Plus
In Exercises 107-lI4, simplify each exponential expression.  Assume that variables represent nonzero real numbers.
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In Exercises lI5-lI8, solve each equation. Express the solution set in scientific notation.
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	Application Exercises
	~ The graph shows the number of people in the United
States ages 65 and over for the year 2000 and projections beyond. Use 106 for one million and the figures shown Oto solve Exercises lI9-122. Express all answers in scientific notation.

U.S. Population, Ages 65 and Over

Year

Source: U.S. Bureau of the Census
119.	How many people 65 and over will there be in 2025?
120.	How many people 65 and over will there be in 2050?
121.	How many more people 65 and over will there be in 2100 than in 2000?
122.	How many more people 65 and over will there be in 2050 than in 2000?

Our ancient ancestors hunted for their meat and expended a great deal of energy chasing it down. Today, our animal protein is raised in cages and on feedlots, delivered in great abundance nearly to our door. Use the numbers shown below to solve Exercises 123-126. Use  for one million and  for one billion.

Overproteined	

600
millon
Big Mac
consumed by
American at
McDonald’s
Each year	
8
billon
Chickens
Raised for
Food each
Yaear in the
U.S.
	
127

Chickens
eaten per
second in
America
	
20
billion
Hot dogs
Consumed by
Americans
Each year

Source: Time, October 20, 2003
In Exercises 123-124, use 292 million, or , for the U.S. population. Express answers in decimal notation, rounded to the nearest whole number.
123.	Find the number oí hot dogs consumed by each American in ayear.
124.	If the consumption oí Big Macs was divided evenIy among all Americans, how many Big Macs would we each consume in ayear?