socials
posted by Mohammad .
wat r main factors of population change?
jobs people get? i really not understand this.
what meant by exponential rate of growth? rule of seventy?
i think it means rapid rate of increase as each generation doubles in size. rule of seventy mean way to estimate number of years it takes for population growth to double in size. it state that doubling time is approx. equal to seventy divided by the growth rate,in percent per year.
how i make rule of seventy definition shorter?

Population change means the increase or decrease in the total number of people living in a country. The main factors of population change are:
the number of children couples have
the number of deaths
the number of people who emigrate
the number of people who immigrate.
Your answer for the last question is good. You can't really make it shorter.
http://ca.answers.yahoo.com/question/index?qid=20081217153126AAOWiPO 
thank you very much ms. sue :)

I have usually heard the "rule of seventy" referred to as the "rule of seventytwo"