Mike used 27 nails to build a chair. he used 14 more nails to build a table than he used to build the chair. how many nails did mike use to build the table? use any strategy to solve. explain your solution.

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.