ABSTRACT
Do the students who spend the most time studying achieve the highest marks in examinations and do those who spend the least time studying get the lowest marks? What we are asking here is whether the variable study time correlates with the variable examination performance. If we found that this was the case then we would say that there is positive correlation between the variables, that is, as a score on one variable increases so the corresponding score on the other variable does the same. Sometimes we find a correlation between two variables where as one goes up the other goes down. This is termed a negative correlation. We are likely to find a negative correlation between smoking and health as the more a person smokes the less healthy that person tends to be.
