notes ch 7

Ch. 7: Scatterplots, Association, and Correlation Scatterplots ? display quantitative data and show patterns, trends, relationships, and even the occasional extraordinary value often used to determine if there is an association between two variables direction ? negative: a pattern that runs from the upper left to the lower right positive: a pattern that runs from the lower left to the upper right form ? linear: a straight line relationship, appears as a cloud or swarm of points stretched out in a generally consistent, straight form if the relationship isn?t straight, but curves gently, while still increasing or decreasing steadily, we can often find ways to make it more nearly straight if it curves sharply, there is much less we can say about it