f(t)=1.8(1.452)^t t=0 correspond to year2004.
In what year will sales reach 20 billion?

Question

f(t)=1.8(1.452)^t        t=0 correspond to year2004.
In what year will sales reach 20 billion?

anonymous · Answer

you are trying to solve $$20=1.8(1.452)^t$$ for t.
divide by 1.8
$$\frac{20}{1.8}=(1.452)^t$$ take the log of both sides 
$$\ln(\frac{20}{1.8})=\ln((1.452)^t)=t\ln(1.452)$$

anonymous · Answer

solve for t:

$$t=\frac{\ln(\frac{20}{1.8})}{\ln(1.452)}$$

anonymous · Answer

thats what i got, but the answer would be 6.5 so the year 2010,

anonymous · Answer

i get 6.4 so 6.4 years after 2004 is 2010.4 of there abouts.

anonymous · Answer

but the question before asked what are sales in 2010 and my answer was 16.9.....not 20. im confused

anonymous · Answer

maybe be safe and say by 2011

anonymous · Answer

i guess the additional .5 counts!  let me try it.

anonymous · Answer

thanks so much

anonymous · Answer

welcome!