皮皮学，免费搜题
登录
搜题
【简答题】
用甲醛法测得某铵盐中氮的质量分数为5.15%、5.32%、5.22%、5.25%。其平均值为______，标准偏差(s)为______，平均值的标准偏差为______，含氮量在置信度为95%时的置信区间为______。( 已知t 0.05,3 =3.18。)
拍照语音搜题，微信中搜索"皮皮学"使用
参考答案：
参考解析：
知识点：
皮皮学刷刷变学霸
举一反三
【单选题】听力原文：W: I wonder if there's a difference in work attitude--working in a small company or working for a big company. M: Yes, sure there're differences. I guess that you're more...uh...conscious of time...
A.
The differences in work attitudes of employees in big companies and small companies.
B.
The management styles of executives in big companies and small companies.
C.
The percentage of employees involved in top management in big companies and small companies.
D.
The operation on a first-name basis in big companies and small companies.
【单选题】听力原文：W: Good afternoon, sir. M: Good afternoon. W: I wonder if you'd like to answer a few questions. We are doing a market survey. It won't take very long. M: Well, all right. W: Well, it is a questio...
A.
They are talking about making the bed.
B.
They are doing a market survey.
C.
They are talking about reading novels.
D.
They are discussing about recent violence matters.
【单选题】听力原文：W: There are so many children at the school. I wonder how the teacher keeps track of them. M: I used to get cold feet at the thought of teaching a class of 50. Q: What was the man's attitude towa...
A.
Timid.
B.
Hostile.
C.
Enthusiastic.
D.
Sympathetic.
【单选题】听力原文：W: Good evening, Mr. Brown, and welcome to the program. M: Thank you! W: I wonder if you could tell listeners more about the work you do? M: Certainly. W: Mr. Brown, I gather that you work for a ...
A.
At a television studio.
B.
On a radio program.
C.
In a job interview.
D.
In a factory.
【简答题】习惯型消费人群属于( )主导人群
【单选题】听力原文：W: Good evening, Mr. Brown, and welcome to the program. M: Thank you! W: I wonder if you could tell listeners more about the work you do? M: Certainly. W: Mr. Brown, I gather that you work for a ...
A.
At a television studio.
B.
On a radio program.
C.
In a job interview.
D.
In a factory.
【单选题】When the novelist Jodi Picoult was approached to write a few installments of the 'Wonder Woman' comics series, her first_____was to take the character out of her trademark.
A.
conspiracy
B.
subversion
C.
impulse
D.
dissipation
相关题目：