Plot every person in the world on a two dimension grid. Dimension x is awesomeness, dimension y is crappiness of crappiest job. Vast majority of people will b

Plot every person in the world on a two dimension grid. Dimension x is awesomeness, dimension y is crappiness of crappiest job. Vast majority of people will be clustered around top left of graph (unawesome people with crappy jobs). But if the mean y value fluctuates upwards as you move to the right along x, then there's a positive correlation, regardless of whether or not there are significantly fewer data points further to the right. Read the "Correlation and linearity" section of the Wikipedia article: http://en.wikipedia.org/wiki/Correlation_and_dependence http://en.wikipedia.org/wiki/Correlation_and_dependence