We note that the women marry on an average about four years 

 and five months younger than the men. Contrary to what we 

 have been told, their mean age at marriage both absolutely, as 

 measured by the standard deviation, and relatively, as measured 

 by the coefficient of variation is more variable than that of men. 

 The difference in standard deviations for the ungrouped material 

 is 2.51 ± .93 and for the grouped records 3.22 ± .92. These are 

 2.71 and 3.49 times their probable error, and hence perhaps 

 significant. For the coefficient of variation, the differences by 

 the two methods are 1.52 ± .31 and 1.74 ± .31. These are 5.69 

 and 4.96 times their probable errors and their significance is 

 even more probable than those for the standard deviations. 



The correlation coefficient from the grouped data by the prod- 

 uct moment method, using the means and standard deviations 

 given above, is 



