从一个班级中任取18名学生,测得体育成绩如下(单位:分) 81 76 85 90 82 79 84 86 83 80 79 96 90 81 82 87 81 83 样本方差等__________.
A.79
B.81
C.83
D.85
单词 单词解释 (选择搭配题)
76. GMT A. run slowly
77. study B. in a word
78. jog C. polite social habits
79. manners D. Greenwich Mean Time
80. share E. a word that means Christmas
81. white lie F. to use, pay, have, etc.,withothers
82. Xmas G. having bad luck
83. in short H. a room in a house that is used for work or study
84. takeaway I. a lie that you tell in order to avoid hurting someone’sfeelings
85. unlucky J. a meal that you buy at a shop or restaurant to eat at home
76题——————
77
78
79
80
81
82
83
84
85
请帮忙给出每个问题的正确答案和分析,谢谢!
从生产一批袋装牛肉松中随机抽取10袋测得重量如下,(单位:克) 76 90 84 86 81 87 86 82 85 83则样本方差等于