Nayland College Mathematics  'More than just a school'  



7 
Describing the ScatterPlot Relationship Describe the relationship seen: Whether the relationship is POSITIVE or NEGATIVE and what this means in context. The STRENGTH of the relationship (or little relationship) Is the relationship LINEAR of not? Is the scatter from the trend line even or not. Are there any groups? Scatter Plot Generator (allow macros) 
Describing Class notes, Blank notes pg287 Ex18.01, pg363 Ex26.01 
What do I look for in scatter plots? Trend 

Do you see: a linear trend… 
or a nonlinear trend? 
Do you see: a positive association… as one variable gets bigger, so does the other 
or a negative association? as one variable gets bigger, the other gets smaller

Scatter 

Do you see: a strong relationship… little scatter 
or a weak relationship? lots of scatter 
Do you see: constant scatter… roughly the same amount of scatter as you look across the plot 
or nonconstant scatter?
the scatter looks like a “fan” or “funnel”

Scatter Plot Generator (allow macros) Positive correlation (relationship): Weak correlation (relationship): Negative correlation (relationship): No correlation (relationship): Strong correlation (relationship): Linear correlation (relationship): When looking at a scatter graph we can ask two questions:Is there a relationship between the two data variables? How close does the data fit this relationship? To answer these questions we use… Correlation: Deciding how closely the data fits the relationship 