问题 问答题 简答题

羊毛制品,在处理前后分别抽样分析其含脂率如下:

处理前,xi:0.19,0.18,0.21,0.30,0.41,0.12,0.27

处理后,yi:0.15,0.13,0.07,0.24,0.19,0.06,0.08,0.12

假定处理前后的含脂率都服从正态分布,且标准差不变,试问在处理前后含脂率的平均值是否有显著变化?

(a=0.05)

答案

参考答案:

所以,拒绝原假设H0,即认为处理前后含脂率的平均值有显著变化,但由于,因此可认为处理后含脂率的平均值显著下降。

阅读理解

阅读理解。

 Dear Peter,

     I know that you are coming to Hefei next week. Welcome to my home. Let me tell you the way to my

 house. You will live in Changjiang Hotel on Changjiang Street, won't you? OK! Changjiang Street is a

 famous and busy street in our city. You can start from your hotel and go straight along Tongcheng Street. 

 You pass two small streets: Hongxing Street and Lujiang Street. When you see an overbridge (高架桥),

 please turn right and go along Huangcheng Street. It's an old street, but it's clean. There's a big park on

 the street. It's beautiful and clean. When you get to Jinzhai Street, please turn left and go along it. You

 will  pass Wuhu Street and Tunxi Street. Then you can see a KFC on your right. There's a supermarket

 across from the KFC and my house is near the supermarket. There's a pay phone in front of the KFC.

 You can call me there and I will go to meet you.

     I hope you will have a good trip.

                                                                                                     Yours,

                                                                                                      Li Li

1. Where will Peter live in Hefei?

    A. Li Li's room    

    B. Changjiang Hotel

    C. Anhui Hotel  

    D. His friend's house

2. How is Changjiang Street by Li Li's words?

    A. It's beautiful.  

    B. It's famous.    

    C. It's old.      

    D. It's famous and busy.

3. How many streets are mentioned (提及) in this letter?

    A. 6       

    B. 7           

    C. 8         

    D. 9

4. How is the park?

    A. It's old but it's clean.    

    B. It's on Tongcheng Street.

    C. It's beautiful and clean.   

    D. It's quiet and dirty.

5. Where's the KFC?

    A. It's near Li Li's home.            

    B. It's across from the pay phone.

    C. It's across from the supermarket.    

    D. It's between the supermarket and the pay phone.

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