Вивчаючи статистику

5. Write out the definitions out of the texts:
Cardinal numbers; ordinal numbers;
population; sample.
6. Complete the following sentences:

• 
  ‘Cardinal’ in statistics is not a person ….
  
• 
  Cardinal numbers are 1, 2, 3 and so on, and …..
  
• 
  An ordinal number describes ….
  
• 
  They express order or ranking, and …..
  
• 
  Most of the statistical techniques created for the analysis of quantitative …
  
• 
  In statistics, the term ‘population’ has a much …
  
• 
  The complete set of people or things that is of interest to …
  
• 
  A sample is therefore a smaller group of people or ….
  
• 
  You need to be clear about whether your data are ….
  
• 
  Most of statistics concerns using sample data to make ….
  

7. Ask 10 general questions to the text.
8. Give examples of:
Cardinal numbers; population;
ordinal numbers; sample.
9. Summarize the contents of the text in 10 – 15 sentences. Use the expressions:
Our topic deals with...;
To begin with, I’ll consider …
First I’ll describe …
Now I’ll pass to …
Finally ….
To conclude …
* * * * *
Sample size: Sample size is perhaps the most important factor in controlling margin of error. The sample size is in the denominator of the standard error, meaning that as your sample size increases, the standard error goes down, and that’s why the margin of error goes down. This result makes sense, because having a larger sample means having more information in your analysis, which should lead to greater precision. As the sample size decreases, the margin of error goes up, because you have less information to work with and that makes for less-precise results.
Standard deviation in the population: Standard deviation is close to the average distance from the mean. If the population you took your sample from has a large amount of variability, the standard deviation is large, and the margin of error for your statistic goes up (because standard deviation is in the numerator of the margin of error). If the population is more homogeneous, your sample results are more homogeneous as well, and the margin of error goes down (because the standard error gets smaller).