Question

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?

Answer 1

Answer)

a) It is mentioned in the question that, the birth rate is 13/1000

that is 13 births per 1000 people

so first we will convert the 309 million(present population into 1000)

as there are 1000000 in one million

so in 309 million, there are 1000000*309 thousand

= 309000000

so we have 309000 * 1000

as there are 13 births per 1000

so there will be 13*309000 births per 309000000

= 4017000

b)

7.4 deaths per 1000

that is 7.4 deaths per 1000

so first we will convert the 309 million(present population into 1000)

as there are 1000000 in one million

so in 309 million, there are 1000000*309 thousand

= 309000000

so we have 309000 * 1000

so

7.4*309000 deaths per 309000*1000 or 309 million

= 2286600

c)

total population = 309000000

total number of births = 4017000

so total population now = 309000000 + 4017000

now we need to subtract the total number of deaths in order to find the present population

total number of deaths = 2286600

present population = 309000000 + 4017000 - 2286600

310730400

d)

as us population actually increased by 3.5 million

so 309 + 3.5 = 312.5 million

or converting it into thousands = 312.5*1000000 = 312500000

this is the actual population

but in part c we calculated 310730400 (not counting immigration or emigration)

so the total number of immigrants = 312500000 - 310730400

= 1769600

and total population growth is 3.5 million or 3500000

so the proportion of the overall population growth due to immigration = 1769600/3500000

= 0.5056