20 points pls match the vocabulary word with its correct definition: question 2 options: lurking variable line of best fit correlation coefficient correlation causation 1. a third variable affecting the relationship between two variables being studied. 2. another name for a least squares regression line. 3. represented with the variable r. a number used to describe direction and strength of the association between two variables. 4. the relationship between two variables. it can also be referred to as "association". 5. the relationship between two variables when a change in one variable causes a change in the other variable.

The correct couples are:
1) Lurking variable
Lurking variables are random variables related to the variables you want to study and which affect them. Their effect is often unnoticed (that is why they are lurking), but they make stronger or weaker the relationship between the explanatory and responsive variables.

2) Line of best fit
The "line of best fit" is the straight line that best represents the data in a scatter plot. The least squares method provides the steps needed to find which line minimize the difference between the expected and the observed values. Therefore, "line of best fit" and "least squares regression line" are synonymous.

3) Correlation coefficient
A correlation coefficient is a number that represents the statistical relationship between two variables. Pearson's coefficient r is a measure of the strength and direction of the linear relationship between two variables.  

4) Correlation
An association is, in statistics, any relationship between two variables. A correlation is a measure of how strongly two variables have a linear relationship with each other. Therefore, "correlation" and "association" are synonimous.

5) Causation
The term "causation" means that there is a "cause and effect" relationship between two events, meaning that one event occurs because an other event has occured. Hence, there is a causal relationship between the two events.