Hendy and Charles (1970) study the change in silver content in Byzantine coins. During the reign of Manuel I (1143-1180) there were several mintings. We consider the research hypothesis that the silver content changed from the first to the fourth coinage. The data consists of nine coins identified from the first coinage and seven coins from the fourth. We suppose that they are realizations of random samples of coins from the two populations. The percentage of silver in each coin is given below


 I   IV
5.9  5.3
6.8  5.6
6.4  5.5
7.0  5.1
6.6  6.2
7.7  5.8
7.2  5.8
6.9  
6.2 

Regression format

 0  5.9 
 0  6.8
 0  6.4
 0  7.0
 0  6.6
 0  7.7
 0  7.2
 0  6.9
 0  6.2
 1   5.3
 1   5.6
 1   5.5
 1   5.1
 1   6.2
 1   5.8
 1   5.8