Quick look at the star (along with the realization I might actually need glasses):
STARS
Light =6
Med =18
DarkA = 48
Background = 12+36 =48
HEXAGONS
Background = 1+12+25=38
Medium = 19
DarkB = 6 (looks like a different fabric than the one in the star)
So all you need to do is figure out the approx finished dimension of a star and hex to know how many you want on your quilt,
and then multiply that by the numbers above (I'd recheck my count of the hexies)
and divide it by 80
(and then, if you want, multiply that by 4 if you want to use yardage).
FWIW, IMHO, making the additional hexies for the background isn't really that much more work since you're making the stars anyway.
And it will, in the end, look way cooler if the entire quilt is hexies (except for a border if you want) rather than appliqueing it on a background.