To model the number of clients \( y \) after \( x \) years with an initial number of clients \( P = 254 \) and a growth rate of \( r = 2.3% = 0.023 \), you can use the formula for exponential growth:
\[ y = P \cdot (1 + r)^x \]
Substituting the values into the equation, we have:
\[ y = 254 \cdot (1 + 0.023)^x \]
This simplifies to:
\[ y = 254 \cdot (1.023)^x \]
Therefore, the exponential function that models the number of clients after \( x \) years is:
\[ y = 254 \cdot (1.023)^x \]