Answer:
f(x) = 120(23/12)^(x-6)
Explanation:
One way to write the model is ...
f(x) = f(x1)·(f(x2)/f(x1))^((x -x1)/(x2-x1))
Filling in the given numbers, this is ...
f(x) = 120·(230/120)^((x-6)/(7-6))
f(x) = 120(23/12)^(x-6)
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Comment on this model
This could be written in the form ...
f(x) = a·e^(bx)
but the constants "a" and "b" would be approximations to their irrational values. We have elected to write the model with exact values in a form that reproduces the given two points exactly.