Which labeled national capital is about 400 miles Southeast of Machu Picchu?

Tucked away in the rocky countryside northwest of Cuzco, Peru, Machu Picchu is believed to have been a royal estate or sacred religious site for Inca leaders, whose civilization was virtually wiped out by Spanish invaders in the 16th century.

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.