题目

1.People consider ________(狐狸) as clever but sly animals. 2.The tribesmen were armed with________(矛) and shields. 3.He is busy________(除草) in the garden. 4.The message travels along the________(神经) to the brain. 5.He likes to watch a________(魔术师) performing tricks. 6.But the________(铸铁制的) rail by the side should be European in style. 7.Your invention is clever,but not________(实用). 8.It's known that the price________(包括) postage charges. 9.The report's conclusions were already________(熟悉的) enough to the government. 10.These 某学校课题小组为了研究学生的数学成绩与物理成绩之间的关系,随机抽取高二年级20名学生某次考试成绩(满分100分)如下表所示:序号1234567891011121314151617181920数学成绩9575809492656784987167936478779057837283物理成绩9063728791715882938177824885699161847886若单科成绩85分以上(含85分),则该科成绩为优秀.(1)根据上表完成下面的2×2列联表(单位:人):数学成绩优秀数学成绩不优秀合计物理成绩优秀物理成绩不优秀合计20(2)根据题(1)中表格的数据计算,有多大的把握,认为学生的数学成绩与物理成绩之间有关系?(3)若从这20个人中抽出1人来了解有关情况,求抽到的学生数学成绩与物理成绩至少有一门不优秀的概率.参考数据:①假设有两个分类变量X和Y,它们的值域分别为{x1,x2}和{y1,y2},其样本频数列联表(称为2×2列联表)为:y1y2合计x1aba+bx2cdc+d合计a+cb+da+b+c+d则随机变量,其中n=a+b+c+d为样本容量;②独立检验随机变量K2的临界值参考表:P(K2≥k)0.500.400.250.150.100.050.0250.0100.0050.001k0.4550.7081.3232.0722.7063.8415.0246.6357.87910.828
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