Math 143 C/E, Spring 2001
IPS Reading Questions
Chapter 6, Section 2

1. The two main statistical inference procedures are level C confidence intervals and tests of significance. Explain the different goals that these two procedures are used to attain.

   
   
   
   
   
   
   
   
   
   
   
   
   
   
   

2. Just what do statisticians consider a “small” probability? In the discussion following Example 6.6, a probability of 0.01 is small enough for the authors to “reject the (null) hypothesis” that Tim has not gained weight, but in Example 6.7, they say that a probability of 0.16 is “not particularly small”. Just where do they draw the line?

   
   
   
   
   
   
   
   

3. In Examples 6.6 and 6.7, a one-sided alternative hypothesis was used, but in Example 6.11 it is a two-sided one. What seems to be the distinction that causes one to decide on the type of alternative hypothesis?

   
   
   
   
   
   
   
   

4. If the P-value comes in lower than the (predetermined) significance level, then you reject the null hypothesis. If the P-value comes in higher, should you accept it?

   
   
   
   
   
   
   
   

5. Why is it more informative to report the P-value for an hypothesis test than to report that the hypothesis test led to rejection of the null hypothesis with significance level a?