The Grapefruit Data

Grapefruit sales were measured for eight grocery stures at three price levels. The multivariate data format is more natural, but for the classical mixed model and covariance structure approaches to repeated measures, proc glm and proc mixed want each value of the response variable to be on a separate line.

Multivariate format

 Store   sales1    sales2    sales3
   1      62.1      61.3      60.8 
   2      58.2      57.9      55.1 
   3      51.6      49.2      46.2 
   4      53.7      51.5      48.3 
   5      61.4      58.7      56.6 
   6      58.5      57.2      54.3 
   7      46.8      43.2      41.5 
   8      51.2      49.8      47.9 

Univariate format

 Store   Price   Sales   
   1      1      62.1  
   1      2      61.3  
   1      3      60.8  
   2      1      58.2  
   2      2      57.9  
   2      3      55.1  
   3      1      51.6  
   3      2      49.2  
   3      3      46.2  
   4      1      53.7  
   4      2      51.5  
   4      3      48.3  
   5      1      61.4  
   5      2      58.7  
   5      3      56.6  
   6      1      58.5  
   6      2      57.2  
   6      3      54.3  
   7      1      46.8  
   7      2      43.2  
   7      3      41.5  
   8      1      51.2  
   8      2      49.8  
   8      3      47.9  

These data are from a homework problem in Applied linear statistical models (2005, 5th edition) by Kutner et al.