In 2007, the world's population reached 6.7 billion and was increasing at a rate of 1.2% per year. assume that this growth rate remains constant. (in fact, the growth rate has decreased since 1987.)

(a) write a formula for the world population as a function of the number of years since 2007. (note: use the general exponential function.)

Population growth rate is the rate in which the number of people increase in a given amount of time. The correct formula for the world population as a function is P=6.7(1.012)^t. P stands for the total world population.  Small t is represented by the unit time period.

no , per capita income is not a true measure of the development because: -it only tells us about average income not how income is distributed among the people.it only give us an idea of the economic aspect.it is only at the qualitative basis.moreover, income is not only the way of development other factors are also as much as important as income.