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#ef605c2f-5039-4776-996a-5b2c8abd6821基础填空题独立事件统计与概率

9.已知离散型随机变量XX的分布列如下:
------------------------- ------------------------- ------------------------- -------------------------
XX 0 1 2
PP xx 4x4x 5x5x
------------------------- ------------------------- ------------------------- -------------------------
由此可以得到期望E(X)E(X)与方差D(X)D(X)分别为((  ))