Population Calculation Problems

A metropolitan area of 100,000 people has 2,000 births, 500 deaths, 200 emigrants, and 100 immigrants. Calculate the population growth rate.

• 1.2 percent

• 1.4 percent

• 1.6 percent

• 1.8 percent

Answer explanation

To calculate the population growth rate, we need to consider the number of births, deaths, emigrants, and immigrants.

Here's how you can do it step-by-step:

2. Calculate the natural increase:

   • Natural increase = B- D

   • Natural increase = 2,000 - 500 = 1,500

4. Calculate the net migration:

   • Net migration = I - E

   • Net migration = 100 - 200 = -100

6. Calculate the total population change:

   • Total population change = Natural increase + Net migration

   • Total population change = 1,500 -100 = 1,400

8. Calculate the population growth rate:

   • Population growth rate = (Total population change / Initial population) × 100%

   • Population growth rate = (1,400 / 100,000) × 100%

   • Population growth rate = 0.014 × 100%

   • Population growth rate = 1.4%

So, the population growth rate for the metropolitan area is 1.4%.

Tags

NGSS.MS-LS2-1

In 2012, there were 20 births per 1,000 people and 5 deaths per 1,000 people in Peru. Calculate the approximate doubling time of Peru's population.

• 5 years

• 15 years

• 47 years

• 72 years

Answer explanation

We are going to model the exponential growth curve, or the part of the logistic curve where a population is growing at its biotic potential (before pressure begins due to environmental resistance).

Rather than using a specific exponential equation for this, we can use the rule of 70 as long as the growth rate is <15%. The main trick with rule of 70 is that you actually calculate with the number from the percentage, not its decimal value.

So first we find the annual growth rate:

Growth rate=Birth rate−Death rate (r=b-d)

Growth rate= 20−5 = 15 per 1,000 people (from the prompt, we know that it's per 1,000, and 'per' is short for this symbol '/', so we'll divide).

We convert the growth rate (r) to a %:

Growth rate=(15/1000)*​100=1.5%

Then we use rule of 70, which is 70 divided by the numerical value of the percent growth rate.

Doubling time=(70/1.5)=46.67

Tags

NGSS.HS-LS2-2

The town of Fremont has a population of 2,000. In 2019, the town has 50 deaths, 20 immigrants, and 30 emigrants. The town's population growth rate is 4.5%. Calculate the crude birth rate in 2019.

• 70

• 75

• 95

• 105

Answer explanation

Net change = Pop. growth rate × Initial pop.

Net change = 0.045×2000 = 90

Notice, when we calculate the net change, the percentage must be converted to a decimal. The only time you'll use the numerical value of the percentage is during rule of 70.

Net change = (B−D)+(I−E)

90=(B−50)+(20−30)

90=B−60

-B=-90-60

B=90+60

B=150

CBR=(Number of births​/Total Pop)×1000

CBR=(150​/2000)×1000=75

The town of Fremont has a population of 2,000. In 2019, the town has 50 deaths, 20 immigrants, and 30 emigrants. The town's population growth rate is 4.5%. Calculate the approximate doubling time of Fremont.

• 16 years

• 22 years

• 45 years

• 88 years

A country has a net immigration rate of 3 per 1,000, a CBR of 9 per 1,000, and a CDR of 11 per 1,000. Calculate the growth rate of this country.

• 0.1 percent

• 0.2 percent

• 0.5 percent

• 1 percent

According to the 2010 census, Cedar Rapids contained 126,326 people. In 2011, there were an estimated 127,904 people. This translates to a growth rate of 1.2%. Using this growth rate, calculate the predicted 2012 population (rounded to the nearest whole number).

Loboville is an island of 4000 square miles off the coast ot Los Amigos. There are currently 250,000 inhabitants of Loboville. Last year, there were 12,000 new children born and 10,000 people were recorded as deceased. Identify the current population of Loboville.

Loboville is an island of 4,000 square miles off the coast ot Los Amigos. There are currently 250,000 inhabitants of Loboville. Last year, there were 12,000 new children born and 10,000 people were recorded as deceased. Calculate the current population density (round to the nearest whole number).

Loboville is an island of 4000 square miles off the coast ot Los Amigos. There are currently 250,000 inhabitants of Loboville. Last year, there were 12,000 new children born and 10,000 people were recorded as deceased. Calculate the birth rate of Loboville (round to the tenths place).

Loboville is an island of 4000 square miles off the coast ot Los Amigos. There are currently 250,000 inhabitants of Loboville. Last year, there were 12,000 new children born and 10,000 people were recorded as deceased. Calculate the death rate of Loboville (round to the tenths place).