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JamenS
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HELP PLZ
The amount of freight transported by rail in the United States was about 580 billion tonmiles in 1960 and has been increasing at a rate of 2.32% per year since then. (a) Write a function representing the amount of freight, in billions of tonmiles, transported annually (1960 = year 0). (b) Graph the function. (c) In what year would you predict that the number of tonmiles would have exceeded or would exceed 1 trillion (1000 billion)?
 one year ago
 one year ago
JamenS Group Title
HELP PLZ The amount of freight transported by rail in the United States was about 580 billion tonmiles in 1960 and has been increasing at a rate of 2.32% per year since then. (a) Write a function representing the amount of freight, in billions of tonmiles, transported annually (1960 = year 0). (b) Graph the function. (c) In what year would you predict that the number of tonmiles would have exceeded or would exceed 1 trillion (1000 billion)?
 one year ago
 one year ago

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nphuongsun93 Group TitleBest ResponseYou've already chosen the best response.0
2.32% = 0.0232 f(t) = 580(1+0.0232)^t
 one year ago

JamenS Group TitleBest ResponseYou've already chosen the best response.0
You want 580 x 10^9 (1.0232)^N to be one trillion, i.e. 10^12. Thus 580 (1.0232)^N = 10^3 1.0232^N = 1000 / 580 = 1. 17241 Take logs of both sides. N log(1.0232) = log (1.17241) N = 0.06944/0.00995 N = 6.979 (years) So it needs 7 full years from 1960 to reach one trillion. So it occurs in 1967
 one year ago

nphuongsun93 Group TitleBest ResponseYou've already chosen the best response.0
ya, thats correct
 one year ago

nphuongsun93 Group TitleBest ResponseYou've already chosen the best response.0
think you have to do the log calculation again, i got 23.7 years
 one year ago

nphuongsun93 Group TitleBest ResponseYou've already chosen the best response.0
ah 1000/580 = 1.724
 one year ago
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