Answer:
C. the initial number of club members, in hundreds
Explanation:
The general form of such an expression is ...
(initial value)×(growth factor per period)^(number of periods)
The use of 12 in the exponent suggests that the growth factor of 1.02 is an annual factor. If that is the case, for t months, the membership should be modeled as ...
1.8(1.02^(t/12))
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As written, the expression is not an exponential expression. With appropriate parentheses, it might be a good model if t is the number of years (not months), and if the expected growth rate is 2% per month.
1.8(1.02^(12t))