A city’s population, P (in thousands), can be modeled by the equation P=130(1.03)^x, where x is the number of years after January 1, 2000. For what value of x does the model predict that the population of the city will be approximately 170,000?

A)8
B)9
C)10
D)11

Question

A city’s population, P (in thousands), can be modeled by the equation P=130(1.03)^x, where x is the number of years after January 1, 2000.  For what value of x does the model predict that the population of the city will be approximately 170,000?

A)8
		B)9
		C)10
		D)11

anonymous · Answer

Population is given in thousands.
So, divide 170,000 by 1000 = 170
Now P=170
Substitute all the x values given in the options so that you get P=170. When x=9, P=170.
Ans is C)9

anonymous · Answer

P = 170,000
170 000 = 130(1.03)^x
log (170 000) = x log [130(1.03)]
x =  log (170 000) / log [130(1.03)]

hmm... are you sure that the equation was: P=130(1.03)^x with x raised to a power?

anonymous · Answer

yep!

anonymous · Answer

thanks darling (: