How To Position 8 Objects Across Middle Of Screen

I am trying to draw add flowers on a graphics window. I can do this just fine, however the position starts from the far left and goes to the far right. I would like to position the 8 flowers in the center of the screen but can't seem to get the right formula to do so. Here is what I have so far to draw the flower, which is simply a GOval nothing complex:

Java Code:

box.flowers=8;
for (int xpos1 = 10; xpos1 < getWidth() - 40; xpos1 += getWidth() / box.flowers) {
box.drawFlowers(xpos1, 400);
} mh_sh_highlight_all('java');

The box size of the window is 800 by 600. Ideally I would like to place x amount of flowers spread across the middle of the screen. How might I do this???