Give the step-by-step reasoning process and then the final answer. Alan has 8 pine trees in his backyard and each tree drops 200 pine cones. If 30% of the pine cones fall on Alan's roof, and each pine cone weighs 4 ounces, how many ounces of pine cones does Alan have on his roof?
First find the total number of pine cones: 8 trees * 200 pine cones / tree = 1600 pine cones. Then multiply that number by 30% to find how many fall on Alan's roof: 1600 pine cones * 30% = 480 pine cones. Then multiply that number by the weight of each pine cone to find the total weight of the pine cones: 480 pine cones * 4 ounces / pine cone = 1920 ounces.
The final answer: 1920.