Answer to Question #264380 in Statistics and Probability for Seff

Question

Getting acquainted with the essential terms and concepts on correlation, it is now time

for you to explain thoroughly your answers to the following questions.

1. Discuss the different kinds of relationship that are possible between two variables.

2. A study has shown that the correlation between fatigue and irritability is 0.53. Based on

this correlation, the author concludes that fatigue is an important factor in producing

irritability. Is this conclusion justified? Explain.

Answer 1

a.

Direct relationship.

This relationship is where two variables move in the same direction. If one variable increases then the other variable increases and if one decreases then the other decreases also.

Reciprocal relationship

This is a correlation between two variables such that the value of one variable is the reciprocal of the value of the other variable.

Spurious relationship

This is a relationship in which two variables are associated but not causally related due to coincidence or presence of a third factor.

Indirect relationship

This is relationship between two variables which do not not affect each other directly but through a third variable. Two variables with an indirect relationship move in opposite directions. When one variable moves up, the other one moves down.

Association without causation

This relationship means that just because two variables correlate does not mean that one variable causes the other. It implies that the relationship between two variables can be caused by a third factor affecting both of them.

b.

A correlation coefficient of 0.5 to 0.7 indicates a moderate to good relationship. Therefore, a correlation coefficient of 0.53 shows that fatigue is an important factor in producing irritability. Hence the author's conclusion is correct and it is justified.