A function table with six rows and two columns is shown. The two boxes in the first row on the top, from left to right have the entries x and f open parenthesis x closed parenthesis. The second row has the entries three and negative three point five. The third row has the entries four and a blank box. The fourth row has the entries five and five point five. The fifth row has the entries six and ten. The last row has entries seven and fourteen point five. A linear function f(x) is shown in the table. What is the value of f(4) ?

f(4)=