Answer:
 INDONESIA.
Step-by-step explanation:
population of a country is number of people living in a country 
when we see the statistics of the population 
1) CHINA (1.42 Billion )
2) INDIA (1.33 Billion )
 3) UNITED STATES (347 million)
 4) INDONESIA (240 million)
hence, the fourth country with the population of 240 million is INDONESIA.