math question?

Question

A country has a population of 195.7 million people in 2006. The fertility rate is 1.85 children per woman. But in order to sustain the population it has to be 2.1. The life expectancy is 78 years. How do I figure out what the population is going to be in the year 2100?

Answer 1

First, we must understand that the reason why the lifetime birth rate must be be 2.1 instead of 2.0. (2.1 is correct BTW). The reason for the extra 0.1 is because of the people that die before they have children.

I don't know if my logic below is truly accurate, but here goes. We should be able to calculate this amount by figuring out what would happen in a single year, and then raising that multiplier to the power of years and then multiply by the current population.

The average number of children a couple will have in a single year would be 1.85 / 78 = times 2.0 / 2.1 to account for the death / infertile factor = .022588522 CPY. So in one year there should be an increase in population due to child births by 195.7 / 2 (couples only) * 0.022588522 = about 2.21 million. Then calculate deaths by 1/78 * 195.7 = about 2.51 million. This gives us about a 300,000 drop in population in a single year, which is about 0.153 percent drop per year. This yields about a 99.8467 percent of the previous year. Take 99.8467 percent to the power of (2100 - 2006) which is about 86.57 percent. So we there will be a population of about 195.7 * 86.57 percent = 169.42 people in 2100.

Answer 2

There isnt enough information to figure it out.

Answer 3

Thanks I feel stupid now. LOL Sorry I was bad at story problems when I was in school, and I never improved.

Answer 4

google math

Answer 5

?

Don't ask me math! My brian is melting. GAUGH!

Do it yourself. Use your calculator.

Answer 6

check your "8 ball" and see if it say "maybe so"