The fraction of an specific group is given by the ratio between the amount of people into this group by the total amount of households. For item a), we want to calculate the fraction of U.S. households in 2005 were married couple households.
item a):
Since in 2005 we had a total of 113,000,000 households and 58,000,000 were married couples, the fraction for item a) is:
To find this as a fraction with 100 as the denominator, we solve for x the following equation:
Solving for x, we have:
item b):
In 2005 we had 30,000,000 of alone individuals households, therefore, the fraction is:
As a fraction of 100, we have:
item c):
The households with a female head in 2005 added up to 14,000,000.
As a fraction of 100, we have: