Exponential functions are in the form [tex]f(x)=a*b^x[/tex], where a is the initial value, b is the growth rate (percent increase) + 1, and x is the number of time periods. Our initial value is 100, and we're given the growth rate + 1 (tripling is the same as increasing by 200%; 200%=2.0; 2.0+1=3). Therefore our function is [tex]p(t)=100*3^t[/tex].