"4 inches" is a length. "7676 square feet" is an area. "4 inches by 7676 square feet"
describes a volume, which is equal to 2,558.67 cubic feet. (= 7676/3, because 4 in = 1/3 ft.) So your question is better put as "How many tons of crushed stone does it take to cover an area of 7676 square feet to a depth of 4 inches?"
The answer depends on the density of the crushed stone. I can't answer that, but I've given your question a clearer phrasing.
25 Yards
221.67 (2dp)
36
64 cuft, about 2 and a third cubic yards
1 yard of 1" crushed stone
25 Yards
221.67 (2dp)
36
However much you want. By suitably varying the thickness, you could, in theory cover the surface of the earth or even a larger area.The 'square feet' of area that it covers is 324/(depth in inches)
A yard equals out to 3 feet, or 36 inches.
64 cuft, about 2 and a third cubic yards
Crushed stone.....
Not sure what 2b is but crushed concrete with 1 1/2" rock will cover about 60 square feet. 15 tons ends up being around 12 cubic yards.
Construction
1 yard of 1" crushed stone
1 cubic yard covers 27/depth in feet square feet.
pebbles, talus, scree, crushed stone, or crushed rock