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JamenS
In 1987, the Australian humpback whale population was 350 and has increased at a rate of about 14% each year since then. Write a function to model population growth. Use a graph to predict when the population will reach 20, 000.
Use the compound interest formula you used in the other question.
sooo wud it b 350(1+1.014)=20000
Almost, the graph you will draw is 350(1+0.014)^n. Then you will go to the point where the graph equals 20,000 and see how many years it has been.
290.99 is the correct answer, did you solve it using the graph?
no im not sure how 2 graph it
http://www.wolframalpha.com/input/?i=350%281.014%29^n+from+-1+to+300
a)P(t) = 350(1.14)t; the population will reach 20,000 in about 30.9 yr. b)P(t) = 350(0.86)t; the population will reach 20,000 in about 19.5 yr. c)P(t) = 350(0.86)t; the population will reach 20,000 in about 39.1 yr.wwwwww d)P(t) = 350(1.14)t; the population will reach 20,000 in about 25.6 yr.
Sorry, 290.99 is not the correct answer at all. The interest is 14% (which is 1.14), not 1.4% (which is 1.014). If you put 1.14 into the formula instead of 1.014 you should get the correct answer. Let me know how it goes.
The answer on my calculator is 30.87543347. The correct rounding of this to one decimal place is 30.9. So the answer is A.