please help quickly

Use the graph to write an explicit function to represent the data and determine how much money Taryn earned in week 5. (4 108) 8 8 9 2 8 8 8 9 8 Money Earned (in dollars) (3,36) (1,4) (2,12) Number of Weeks f(n) = (3)" -1; f(5) = 81 f(n) = 4(3)0 +1; f(5) = 2,916 U f(n) = 4(3)"; f(5) = 972 fin) = 4(3)0 - 1; f(5) = 324