Question

A researcher measures driving distance from college and weekly expense on gas for a group of commuting college students. What kind of correlation is likely to be obtained for these two variables?

Answer 1

Strong, Positive, Linear Relationship

Reasoning:

• Positive Relationship

If the driving distance from the college is more then the expense of the petrol would also be greater.

• Linear Relationship

This is because there's will always be a direct proportional relationship between petrol and distance. (there's no way that for longer distances the petrol usage would eventually drop down)

• Strong.

In MOST cases the students will have similar experiences, for e.g if 10 students live equal distances away from college, their petrol expenses would also be similar.

side note (optional, extra information):

some other variables are also at play here. These are one of those 'odd' or 'seldom occouring' instances which may cause 'outliers' in our plot. One of them may be traffic experienced through the weeks, which may cause the usage of more petrol even for the students who live near the college. Or even cause different petrol expenses for students who live on similar distances from the college.

These variables are important to keep in mind when thinking about correlation. So that we have a better understanding that the linear relationship is never perfect, but a close representation of reality.

Hope this helps :)