Task: Question Answering
Input (English): Question: When an experimental design is carried out, it is fundamentally sought: 
 Options:  <1> Know better the average of the results obtained and repeated in an experiment. <2> Know better the median of the results obtained in an experiment. <3> Identify better the factors that can affect the experiment. <4> To better identify the regression equations in an experiment. <5> To know better the standard deviation of the different data in the experiment.
Output (English): 3