【单选题】一个常染色体平衡易位携带者最常见的临床表现是
【单选题】— Please tell Jane she has won the first prize in the English contest. — _____! She never did so well before. [ ]
【单选题】Air conditioners made in China have won worldwide attentions and GREE has become popular name.
【简答题】总体X服从正态分布N(μ,σ 2 )。(X 1 ,X 2 ,…,X n )是来自总体X的简单随机样本, 是样本均值,S 2 是样本方差。在以下条件下分别试求总体均值μ的1-α置信区间: (1)假设总体方差 已知; (2)假设总体方差σ 2 未知。
【简答题】A.He has never been to the laboratory. B.The woman won't be late. C.He wants to stop and ask for directions. D.The program in the laboratory has already begun.
【单选题】— Please tell Bruce he has won the first prize in the maths contest. — ________! He never did so well before. [ ]
【多选题】关于烧结普通砖砌体砌筑施工技术的说法,正确的有______。
A.
砖墙灰缝宽度宜为10mm,且不应小于8mm,也不应大于12mm
B.
砖墙上临时施工洞口,其侧边离交接处墙面不应小于500mm,净宽不应超过1m
D.
砖墙工作段的分段位置,宜设在变形缝、构造柱或门窗洞口处
E.
砖墙每日砌筑高度不宜超过1.8m;雨天施工时不宜超过1.5m
【单选题】一个常染色体平衡易位携带者最常见的临床表现是
【判断题】在总体服从正态分布,总体方差未知的条件下,样本平均值的分布为 t分布
【单选题】问题16-20均以本题为基本条件。假设某次考试的成绩服从正态分布,从中随机地抽取36位考生的成绩,算得平均成绩为66.5分,标准差为15分,问在显著性水平0.05下,是否可以认为这次考试全体考生的平均成绩为70分?并给出检验过程。根据题意,本题是对正态总体参数的假设检验,则下列说法正确的是( )。