China makes up % of the world's population. a. 15 b. 20 c. 63 d. 17

Google says chinas 18%

so I would choose D. 17

None of these are the answer unless you choose the on closest to the actual answer.

Explanation:

The world's two most populated countries, China and India, together constitute about 36% of the world's population. China population is equivalent to 18.47% of the total world population.

this null effect is caused by a weak manipulation and ineffective internal validity. in a scientific study, as the one dr. morimoto is trying to perfom, internal validity refers to the confidence placed in the cause-effect relationship and to how well an experiment is done and able to eliminate confounding variables.        

it should be d or b but i'm sure it's d