:

 	
        Car 1    Car 2    Car 3   Car 4   Car 5    Car 6 

Brand A    125      64       100      38       96      112

Brand B    131      65       103      37       102     115


(For instance, after Car 1 was outfitted with 4 new brand A tires
and then driven for one month, the total wear on the 4 tires was
125/1000th of an inch; after it was driven for one month with new
brand B tires, the total wear on the 4 tires was 131/1000th of an
inch.)  Let the null hypothesis be that tires of brand A and
tires of brand B wear about equally, and the alternative
hypothesis be that tires of brand B are longer-wearing.  Assume
that the six differences in tire wear (like 131 - 125 = 6 and 37
-38 = -1) are a random sample from a large collection of such
differences whose histogram follows the normal curve. If you test
the null hypothesis against the alternative, the P-value should
turn out to be 

 	
 a. less than or equal to .05% 

 	
 b. bigger than .05%, but less than or equal to 2.5% 

 	
 c. bigger than 2.5%, but less than or equal to 5% 

 	
 d. bigger than 5%, but less than or equal to 10% 

 	
 e. bigger than 10%