According to Wolfram|Alpha, the population of Texas has been growing by about $1.92\%$ per year since $1960\text{.}$ In $1960\text{,}$ the population was about $9.624$ million people. Write an exponential formula to model the population of Texas. Here, the input $t$ should be the number of years after $1960\text{,}$ and the output $f(t)$ should be the population in millions. Answer: $f(t) =$