EXAMINING RELATIONSHIPSScatterPlots

SCATTERPLOTS

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

SCATTERPLOT BREAKDOWN 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

SCATTERPLOT BREAKDOWN

SCATTERPLOT INTERPRETATION 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

FDS

INTERPRETING THESE PLOTS IN CONTEXT

# of target practice sessions

# of deer shot D(irection): Positive

More Practice Sessions = More Dead DeerS(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): LinearNo real Clusters to describe (not much context

with form, unless there are clusters to describe)

Volume Level of Music (decibels)

# of Words M

emorized

F: Linear

D: NegativeLouder 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

INTERPRETING THESE PLOTS IN CONTEXT

# of Caffeinated Drinks Consumed

# of Miles R

an in W

eek

FDSNO

NE

NO

NE

NO

NE

There must not be a relationship between caffeine and speed in

a race!!!

WORK

Measuring Up Read Pages 130 -131 #15-17,21-23