SOLUTION: I do not get how to do this nor which of the two formulas below that it needs to be done in. I tried it in both, and could not get it to work as I thought it would. In 1975 t

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: I do not get how to do this nor which of the two formulas below that it needs to be done in. I tried it in both, and could not get it to work as I thought it would. In 1975 t      Log On


   



Question 93974: I do not get how to do this nor which of the two formulas below that it needs to be done in. I tried it in both, and could not get it to work as I thought it would.

In 1975 the population of the Earth was approximately 4 billion and doubling every 35 years. The formula for the population P in year Y for this doubling rate is P (in billions) = 4 ∙2^((y-1975)/35)

The U.S. population in 1990 was approximately 250 million, and the average growth rate for the past 30 years gives a doubling time of 66 years. The above formula for the United States then becomes
P (in millions) = 250 ∙2^((y-1990)/66)

#82. Social science. What will the population of the United States be in 2025 if this growth rate continues?

Answer by scott8148(6628) About Me  (Show Source):
You can put this solution on YOUR website!
the question says "United States" so the second formula applies ... P=250*2^((2025-1990)/66)

P=250*2^(35/66) ... P=361.06