The following table gives the age of husbands and wives at the time of their marriage. Calculate the co-relation coefficient between the ages of husbands and wives :

Ages of wives :-

30-40

40-50

50-60

60-70

Age of Husbands

30-40

20

40-50

50-60

60-70

::

26 •

14

A

--

"-

37

18