The frog population at a lake doubles every three weeks. the population can be modeled by f(x)=15(2)^x and f(6)=960. what does the 15 represent?
a- the population after six weeks
b- the starting population
c- the rate the population increases
d- the number of weeks that have passed

We have to answer what does the 15 represent in the function : f ( x ) = 15 * 2^x, which models the increasing of the frog population at a lake. We know that the frog population doubles every 3 weeks and that: f ( 6 ) = 960. It means that: 15 * 2^ 6 = 15 * 64 = 960. And also f ( 0 ) = 15 * 2^0 = 15 * 1 = 15. Therefore it is a starting population. The 15 represents B - The starting population.