The function f(x) = 15(2)x represents the growth of a frog population every year in a remote swamp. Elizabeth wants to manipulate the formula to an equivalent form that calculates every half-year, not every year. Which function is correct for Elizabeth's purposes? f(x) = 15(2 to the one half power)2x f(x) = 15(22)the x over 2 power f(x) = fifteen halves(2)x f(x) = 30(2)x