Remark
To find the location of the focus, you need to know something about what you are being told about the horizontal line cutting the parabola at y = 4
The general formula for this is v * y = x^2. You need to have a way of finding v
Solve
When x = 4, y = 4 (from the graph)
v * 4 = 4^2
4v = 16
v = 16/4
v = 4
Now what you have is x^2 = 4p * y
4p = 4 because the value in front of y (I called it v) = 4
p = 4/4 = 1
The focus is at h,k + p
The x value of the focus is 0
The y value of the focus is 0 + 1 = 1
The focus is located at (0,1)
The y value of the focus is 0 + 1
