【单选题】从均数等于420,标准差等于21的总体中获得样本量为49的简单随机样本,其样本均数的标准差为
【简答题】. 四、附加题(本题10分,记入总分) 23.若 ,且 满足 ,求 的最小值.
【单选题】According to the classic of tea , tea is defined as ( ).
【多选题】从均数等于420,标准差等于21的总体中获得样本量为49的简单随机样本,其样本均数的标准差为
【单选题】Because of the pioneering significance of The Classic of Tea, _____.
A.
Lu Yu was honored as the Tea Sage
B.
Chinese people began to drink tea
C.
Lu Yu became a well-known poet
D.
people all over the world got to know China
【简答题】附加题(本题10分,选做,分数计入总分,如总分超过100分仍为100分) 已知集合A={x︱x 2 -4mx+2m+6=0,xÎR},若A∩R - ≠Æ,求实数m的取值范围(R - 表示负实数集)。
【单选题】从均数等于420,标准差等于21的总体中获得样本量为49的简单随机样本,其样本均数的抽样分布可以表示为
【简答题】四、附加题(本题满分10分,记入总分) 23. .已知数列 中, , ,求 .
【简答题】四、附加题(本题满分10分,记入总分) 23.设 , ,且 , 求证: .
【单选题】Luyu rated_____ as No. 1 tea of Huainan region and lavished praises on her in The Classic of Tea.
B.
West Lake Dragon Well Tea