1. The number of students present in class & the number of empty chairs

Question

Type of correlation:
Justification:
Independent variable:
Dependent variable:

2. Speed of car & distance traveled to complete stop after brakes are applied

Type of correlation:
Justification:
Independent variable:
Dependent variable:

Answer 1

1. One increases, while the other decreases, students present effects empty chairs

2. both increase together, speed effects distance

An independent variable is the potential stimulus or cause, usually directly manipulated by the experimenter, so it could also be called a manipulative variable.

A dependent variable is the response or measure of results.

I don't know what you mean by "justification."