:3. I borrow a scale from my next door neighbor.  I use it
twice to weigh my cat, obtaining weights of 15 and 17 pounds. 
Assume that the Gauss model obtains, with no bias, and that the
histogram of the error box closely follows the normal curve.  A
95% confidence interval for the weight of my cat is closest to

 	
 a. from 3 to 29 pounds 
 	
 b. from 13 to 19 pounds 

 	
 c. from 14.5 to 17.5 pounds 

 	
 d. from 0 to 20 pounds 

 	
 e. a sample of size two is too small for a 95%    confidence
interval to be found