Analysing two scale variables
Introduction
With two scale variables there are two options. Either you might want to know if there is a relationship (correlation) between the two, or if there is a difference in average between the two. For the first one (the relation) you are at the right place here, but if you want to know if the average (mean) between the two is different then have a look at the paired section here.
To analyse two scale variables on a possible relationship the following steps will be taken:
1) Get an impression for each of the variables by determining the mean and standard deviation for each.
2) Visualise the results using a scatter plot.
3) Use the Pearson product-moment correlation coefficient to determine if, and the direction of a lineair relationship, and the determination coefficient for the strength.
4) Write all parts up in one report.
For each of the steps a separate page has been created. Let's begin with the first page.
Google adds