Total weight of the 8 backpacks = 8 x 14 = 112 pounds
Total weight of the 12 backpacks = 12 x 9 = 108 pounds
Total weight of all the 20 backpacks = 220 pounds
Mean weight of the 20 backpacks = 220 ÷ 20 = 11 pounds
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Answer: The mean weight of the 20 backpacks is 11 pounds
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