The function appears to be a linear function f(x) = mx + b, with m being the slope and b being the intercept.

We can find the slope and intercept using two input-output pairs, for example, (0, 6.8) and (5, 28.8).

To calculate the slope (m):
m = (y2 - y1) / (x2 - x1) = (28.8 - 6.8) / (5 - 0) = 22 / 5

To calculate the intercept (b), we use the equation with the known point (0, 6.8):
b = y - mx = 6.8 - 0 = 6.8

The linear function would approximately be:
f(x) = 22/5 * x + 6.8

