E XAMINING R ELATIONSHIPS ScatterPlots

S CATTERPLOTS Response Variable (dependent) (y) Observed outcome Explanatory Variable (independent) Variable that you change or is changed to note an effect on the response variable Ex: In an effort to improve the performance of his race horses, a horse trainer at Keeneland recorded the amount of grain fed to his horse on race day, over a period of 12 races, and the horse’s finishing times in those races. Identify the Response and Explanatory Variables in this study. Explanatory: Amount of Grain Response: Race Time

S CATTERPLOT B REAKDOWN Axis Explanatory Variable – x axis Response Variable – y axis Describes the relationship between 2 variables Show locations of each individual data value Used to locate patterns and make predictions

S CATTERPLOT B REAKDOWN

S CATTERPLOT I NTERPRETATION FDS – Form, Direction, Strength Form: look for clusters, or lack of…, linear, curve, etc. Explain possible reasons for clusters or pattern Direction: negative or positive Context Positive – As x increases, y increases Negative – As x increases, y decreases Strength: closeness of all points to general form Context What to Look for? DSF describes the pattern of the data Look for Outliers Deviations from the pattern of the graph

I NTERPRETING THESE P LOTS IN C ONTEXT # of target practice sessions # of deer shot D(irection): Positive More Practice Sessions = More Dead Deer S(trength): Strong (all pts tight to linear pattern) Closer to Pattern = Better chance for a strong relationship (cause/effect) between practice and success F(orm): Linear No real Clusters to describe (not much context with form, unless there are clusters to describe) Volume Level of Music (decibels) # of Words Memorized F: Linear D: Negative Louder Music – Fewer Words Remembered S: Moderate (pts form a linear pattern (light spread) Possibly some other factors that effect memorization – Less to do with music

I NTERPRETING THESE P LOTS IN C ONTEXT # of Caffeinated Drinks Consumed # of Miles Ran in Week N O N E N O N E N O N E There must not be a relationship between caffeine and speed in a race!!!

W ORK Measuring Up Read Pages #15-17,21-23