A series of tile patterns is shown below. Consider the function that represents the number of white tiles in each figure.

The correct statements are:
W(n) = 4n+4 represents the function
Input values for the function are natural numbers
Figure 8 will have 36 white tiles.

We write a function expressing the number of white tiles as a function of the figure number.  Writing them as ordered pairs we have:
(1, 8); (2, 12); (3, 16); (4, 20)

The first differences are all equal so this is a linear situation.  Finding the slope of the line we have:
m = (12-8)/(2-1) = 4/1 = 4

In point-slope form, we have
y-8 = 4(x-1)
y - 8 = 4x - 4
y = 4x + 4

To find the number of tiles for any figure, we substitute that value in.  For figure 8, we have y = 4*8 + 4 = 32 + 4 = 36.

This is not continuous, as there is no value for figure 1.1, 1.2, etc; it is whole figure numbers.