Answer: 22.71 million 
Step-by-step explanation:
The labor force refers to both the employed and unemployed populations of a country. In other words it comprises of those who are working and those who are not working but are able to and are currently seeking employment. 
Labor force = Unemployed + Employed 
= 3.4 + 1.72 + 4.4 + 13.19
= 22.71 million 
Those who have not looked for work in sex weeks and above are not considered unemployed. 
Part time employees are considered employed.