Question

The following table gives the ages of husbands and wives 

Age of wives (in years)	Age of husbands (in years)
	20 - 30	30 - 40	40 - 50	50 - 60
15 - 25	5	9	3	-
25-35	-	10	25	2
35-45	-	1	12	2
45-55	-	-	4	16
55-65	-	-	-	4

Find : (i) The marginal frequency distribution of the age of husbands.
(ii) The conditional frequency distribution of the age of husbands when the age of wives lies between
25 - 35.

Answer 1

Age of wives (in years)	Age of husbands (in years)
	20 - 30	30 - 40	40 - 50	50 - 60
15 - 25	5	9	3	-
25-35	-	10	25	2
35-45	-	1	12	2
45-55	-	-	4	16
55-65	-	-	-	4
Total	5	20	44	24

Now, marginal distribution of age of husbands. 

Age (years)	20-30	30-40	40-50	50-60	Total
Number	5	20	44	24	93

Now marginal distribution of husband, when the
age of wives lies between 25 – 35 

Age (years)	20-30	30-40	40-50	50-60	Total
Number	-	10	25	2	37