Mức hao phí nguyên liệu của một loại sản phẩm của một nhà máy là biến ngẫu nhiên có luật phân phối chuẩn. Khảo sát ngẫu nhiên 25 sản phẩm loại này thì nhận thấy độ lệch chuẩn mẫu là 0,263gram/sp. Với độ tin cậy 90% hãy tìm khoảng tin cậy cho độ lệch chuẩn tối thiểu của mức hao phí nguyên liệu của một sản phẩm loại này.

Chia sẻ

Một số câu hỏi khác có thể bạn quan tâm.

• Choose the correct sentence which is built from the words and phrases given:

   English / borrow / words / more than 50 different languages
  
  

• Choose one sentence that has the same meaning as the root one:

  Mary called me because she wanted me to give her some advice.
  
  

• Choose one sentence that has the same meaning as the root one:

  It was not warm enough for us to take a leisurely walk.
  
  

• Choose one sentence that has the same meaning as the root one:

  It was impossible for Jim to complete the exam.
  
  

• Choose one sentence that has the same meaning as the root one:

  This quarrel is likely to lead to a fight.
  
  

• Choose one sentence that has the same meaning as the root one:

  London has dealt with the problems of pollution.
  
  

• Choose one sentence that has the same meaning as the root one:

  The passengers were killed after the plane crash.
  
  

• Choose one sentence that has the same meaning as the root one:

  I tried to drink the coffee, but it was too strong.
  
  

• Choose one sentence that has the same meaning as the root one:

  He went down with flu as soon as he recovered from a fever.
  
  

• Find a mistake in the four underlined parts of the sentence and correct it:

  True friendship is like sound health; it’s value is seldom known until it is lost.